Vitamin D

Discussion in 'Men's Health Forum' started by Michael Scally MD, Jul 27, 2010.

  1. Michael Scally MD

    Michael Scally MD Doctor of Medicine

    Kaur P, Mishra SK, Mithal A. Vitamin D toxicity resulting from overzealous correction of vitamin D deficiency. Clinical Endocrinology.

    Background Vitamin D toxicity, often considered rare, can be life-threatening and associated with substantial morbidity, if not identified promptly.

    Objective To describe clinical and biochemical features, risk factors and management of patients with vitamin D toxicity seen between January 2011 and January 2013.

    Methodology Patients presenting with vitamin D toxicity, between January 2011 and January 2013, at single tertiary care centre in Delhi-NCR, India were included. Evaluation included detailed clinical history and biochemical tests including serum calcium, phosphorus, creatinine, intact parathyroid hormone and 25 hydroxyvitamin D (25(OH)D).

    Results Sixteen patients with vitamin D toxicity were seen. Clinical manifestations included nausea, vomiting, altered sensorium, constipation, pancreatitis, acute kidney injury and weight loss. Median (range) age was 64.5 (42-86) years. Median (range) serum 25(OH)D level and median (range) serum total serum calcium level were 371 (175-1161) ng/ml and 13.0 (11.1-15.7) mg/dl respectively. Overdose of vitamin D caused by prescription of mega doses of vitamin D was the cause of vitamin D toxicity in all cases. Median (range) cumulative vitamin D dose was 3,600,000 (2,220,000-6,360,000) IU.

    Conclusion Our data demonstrate an emergence of vitamin D toxicity as an increasingly common cause of symptomatic hypercalcemia. Irrational use of vitamin D in mega doses resulted in vitamin D toxicity in all cases. Awareness among health care providers regarding the toxic potential of high doses of vitamin D and cautious use of vitamin D supplements is the key to prevent this condition. This article is protected by copyright. All rights reserved.
  2. BBC3

    BBC3 Member

    @Michael Scally MD

    *** How you found any good studies yet on how cholesterol related heart disease RELATES TO SUN EXPOSURE.??

    - Have they put folks out to tan yet to see what the changes are.

    - Have they started to maybe think that not converting skin cholesterol JUST MIGHT cause the blood to supersaturate with CHOLESTEROL..! And genetics dependent of course...

    - Do people that tan better, BUT DONT GET SUN, HAVE HIGH HEART BLOCKAGE RATES..?

    - Do light skinned folks that CAN HANDLE SUN never/less have heart blockages.?? (Keep in mind this is subjective to the ones that just dont go out in sun or not).

    - When you consider the blood composition and potential total component apportionate limits - WHAT ELSE is affected. Hormone blood population?? (as you have posted a lot)

    - WORSE Blood component population and RECEPTOR WASTE or DERIVATIVE CLEARANCE AND ELIMINATION in all conditions.

    - LIVER OVERALL FUCNTION. Incidence of fatty liver to no sun when genetically needed?

    - Does a landscaper never have a choleterol heart blockage and NOT due to exercise alone, but equally due to sun exposure and cholesterol conversion to Vit D.!!?


    - Could Supplemental market Vit D cause a reverse or NeGATIVE feedback at liver and CHANGE CHOLESTEROL PRODUCTION PROFILE POORLY...?!

    - OR - Could it just be another cash crop for the health supp market. Funny how med science wants in too. Perhaps cause of some of the above.? But I do recall how any dose of a twin lab type blended Vit E used to hurt my heart and cause me distress in daily doses over 200. And that was supposed to be the holy grail then.

    **** Has the world always had an ignored vit d deficiency? Cause they seem to all the sudden...! How does it relate to xeno-estrogens and BPA...? -

    "Manufacturers often add different chemicals to plastics to give them the exact characteristics they’re looking for, like flexibility, strength, and reduced production cost. These components can include phthalates, bisphenol A (BPA), polybrominated diphenyl ethers (PBDE) and tetrabromobisphenol A (TBBPA) — all of which alter hormone expression in nonhuman animals and humans."

    While I agree Low Vit D is clearly an ABNORMAL CONDITION and INDICATION which may result in negative health repercussions. We must again REALIZE IT IS ONLY A SYMPTOM.... Symptoms are good for 1 of 5 things...:
    1. Disregarding/Ignoring,
    2. worrying,
    3. Quacking,
    4. making $$.
    5. Educated Meticulous, CAUTIOUS, Un-Biased, & MORALLY SOUND Research and correct TREATMENT, OR Correction of lifestyle causing....

    SURVEY SAYS - (9 out of 10 Americans prefer the first option.)

  3. Michael Scally MD

    Michael Scally MD Doctor of Medicine

    Rajakumar K, Moore CG, Yabes J, Olabopo F, Ann Haralam M, et al. Effect of vitamin D3 supplementation in black and in white children: a randomized, placebo-controlled trial. The Journal of Clinical Endocrinology & Metabolism.

    Context: Dosages of vitamin D necessary to prevent or treat vitamin D deficiency in children remain to be clarified.

    Objective: To determine the effects of vitamin D3 1000 IU/day on serum 25(OH)D, PTH, and markers of bone turnover (osteocalcin and collagen type 1 cross-linked C-telopeptide) in black and in white children; and to explore whether there is a threshold level of 25(OH)D associated with maximal suppression of serum PTH concentration.

    Design: Healthy 8- to 14-yr-old Pittsburgh-area black (N=84) and white (N=73) children not receiving vitamin supplements, enrolled during October through March of 2008 through 2011, were randomized to vitamin D3 1000 IU or placebo daily for 6 months.

    Results: The mean baseline concentration of 25(OH)D was <20 ng/mL in both the vitamin D-supplemented and the placebo group (19.8±7.6 and 18.8±6.9 ng/mL, respectively).

    Mean concentration was higher in the supplemented group than in the placebo group at 2 months (26.4±8.1 vs 18.9±8.1 ng/mL, P<0.0001) and also at 6 months (26.7±7.6 vs. 22.4±7.3, P=0.003), after adjusting for baseline 25(OH)D, race, gender, pubertal status, dietary vitamin D intake, body mass index, and sunlight exposure. Increases were significant only in black children, when examined by race.

    The association between 25(OH)D and PTH concentrations was inverse and linear without evidence of a plateau. Overall, vitamin D supplementation had no effect on PTH and bone turnover.

    Conclusions: Vitamin D3 supplementation with 1000 IU/day in children with mean baseline 25(OH)D concentration <20 ng/mL effectively raised their mean 25(OH)D concentration to ≥20 ng/mL but failed to reach 30 ng/mL. Vitamin D supplementation had no effect on PTH concentrations.
    BBC3 likes this.
  4. BBC3

    BBC3 Member

    I do seem to recall a teacher in elementary grade school making an example of WHY Vitamin D was supplemented in milk using African American Children and folks alike as an example... She stated that there was something that came about after the ritual of the satanic ritual known as SLAVERY / Indentured Servitude :confused::(:mad: The second of these terms being which i think they referred/utilized to feel good about themselves in the South back in the day and after or around the time things started to normalize and slavery was ending. But she stated that she read that Africans which had been brought to the US were not getting their historically "normal" higher sunlight exposure (ezpecially once in school and indoors) and how they presented SEVERE SYMPTOMS associated with Vit D deficiency.!!

    There is no Racial connotoation or simple bigotry applied by me or intended in ANY WAY in this post. I am just having a flashback to something I was "Taught" by an early teacher, and as she was explaining the components which were supplemented in today's milk.

    Anyone know anything about this or have any to add.

    Thank you for the study.:)

  5. BBC3

    BBC3 Member

    Vitamin D and Health

    Vitamin D Deficiency: A Global Concern
    [paste:font size="4"]13) Indeed, in industrialized countries, doctors are even seeing the resurgence of rickets, the bone-weakening disease that had been largely eradicated through vitamin D fortification. (46)

    Why are these widespread vitamin D deficiencies of such great concern? Because research conducted over the past decade suggests that vitamin D plays a much broader disease-fighting role than once thought.

    Being “D-ficient” may increase the risk of a host of chronic diseases, such as osteoporosis, heart disease, some cancers, and multiple sclerosis, as well as infectious diseases, such as tuberculosis and even the seasonal flu.

    Currently, there’s scientific debate about how much vitamin D people need each day. The Institute of Medicine, in a long-awaited report released on November 30, 2010 recommends tripling the daily vitamin D intake for children and adults in the U.S. and Canada, to 600 IU per day. (7) The report also recognized the safety of vitamin D by increasing the upper limit from 2,000 to 4,000 IU per day, and acknowledged that even at 4,000 IU per day, there was no good evidence of harm. The new guidelines, however, are overly conservative about the recommended intake, and they do not give enough weight to some of the latest science on vitamin D and health. For bone health and chronic disease prevention, many people are likely to need more vitamin D than even these new government guidelines recommend.

    Read more about why the IOM’s new vitamin D and calcium guidelines are too low in vitamin D and too high in calcium for bone health.

    [paste:font size="4"]1)

    Correctly applied sunscreen reduces our ability to absorb vitamin D by more than 90 percent. (8) And not all sunlight is created equal: The sun’s ultraviolet B (UVB) rays—the so-called “tanning” rays, and the rays that trigger the skin to produce vitamin D—are stronger near the equator and weaker at higher latitudes. So in the fall and winter, people who live at higher latitudes (in the northern U.S. and Europe, for example) can’t make much if any vitamin D from the sun. (8)

    Read more: what may increase your risk for low vitamin D

    Vitamin D helps ensure that the body absorbs and retains calcium and phosphorus, both critical for building bone. Laboratory studies show that vitamin D can reduce cancer cell growth and plays a critical role in controlling infections. Many of the body’s organs and tissues have receptors for vitamin D, and scientists are still teasing out its other possible functions.

    [paste:font size="4"]VITamin D and OmegA-3 TriaL (VITAL), which will enroll 20,000 healthy men and women to see if taking 2,000 IU of vitamin D or 1,000 mg of fish oil daily lowers the risk of cancer, heart disease, and stroke.

    Here, we provide an overview of some of the more promising areas of vitamin D research, highlighting the complex role of vitamin D in disease prevention—and the many unanswered questions that remain.

    [paste:font size="4"]913)

    A summary of the evidence comes from a combined analysis of 12 fracture prevention trials that included more than 40,000 elderly people, most of them women. Researchers found that high intakes of vitamin D supplements—of about 800 IU per day—reduced hip and non-spine fractures by 20 percent, while lower intakes (400 IU or less) failed to offer any fracture prevention benefit. (13)

    Vitamin D may also help increase muscle strength, which in turn helps to prevent falls, a common problem that leads to substantial disability and death in older people. (1416) Once again, vitamin D dose matters: A combined analysis of multiple studies found that taking 700 to 1,000 IU of vitamin D per day lowered the risk of falls by 19 percent, but taking 200 to 600 IU per day did not offer any such protection. (17)

    A recent vitamin D trial drew headlines for its unexpected finding that a very high dose of vitamin Dincreased fracture and fall risk in older women. (18) The trial’s vitamin D dose—500,000 IU taken in a once-a-year pill—was much higher than previously tested in an annual regimen. After up to 5 years of treatment, women in the vitamin D group had a 15 percent higher fall risk and a 26 percent higher fracture risk than women who received the placebo.

    It’s possible that giving the vitamin D in one large dose, rather than in several doses spread throughout the year, led to the increased risk. (18) The study authors note that only one other study—also a high-dose, once-a-year regimen—found vitamin D to increase fracture risk; no other studies have found vitamin D to increase the risk of falls. Furthermore, there’s strong evidence that more moderate doses of vitamin D taken daily or weekly protect against fractures and falls—and are safe.

    So what is the significance of this study for people who want to take vitamin D supplements? A reasonable conclusion would be to continue taking moderate doses of vitamin D regularly, since these have a strong safety record, but to avoid extremely high single doses. This recent finding does present a challenge to scientists who will work to understand why the extreme single dose appears to have adverse effects.

    [paste:font size="4"]19) So perhaps it’s no surprise that studies are finding vitamin D deficiency may be linked to heart disease. The Health Professional Follow-Up Study checked the vitamin D blood levels in nearly 50,000 men who were healthy, and then followed them for 10 years. (20) They found that men who were deficient in vitamin D were twice as likely to have a heart attack as men who had adequate levels of vitamin D. Other studies have found that low vitamin D levels were associated with higher risk of heart failure, sudden cardiac death, stroke, overall cardiovascular disease, and cardiovascular death. (2124) How exactly might vitamin D help prevent heart disease? There’s evidence that vitamin D plays a role in controlling blood pressure and preventing artery damage, and this may explain these findings. (25) Still, more research is needed before we can be confident of these benefits.

    [paste:font size="4"]26) Many scientific hypotheses about vitamin D and disease stem from studies that have compared solar radiation and disease rates in different countries. These can be a good starting point for other research but don’t provide the most definitive information. The sun’s UVB rays are weaker at higher latitudes, and in turn, people’s vitamin D levels in these high latitude locales tend to be lower. This led to the hypothesis that low vitamin D levels might somehow increase colon cancer risk. (2)

    Since then, dozens of studies suggest an association between low vitamin D levels and increased risks of colon and other cancers. (1,27) The evidence is strongest for colorectal cancer, with most (but not all) observational studies finding that the lower the vitamin D levels, the higher the risk of these diseases. (2838) Vitamin D levels may also predict cancer survival, but evidence for this is still limited. (27) Yet finding such associations does not necessarily mean that taking vitamin D supplements will lower cancer risk.

    The VITAL trial will look specifically at whether vitamin D supplements lower cancer risk. It will be years, though, before it releases any results. It could also fail to detect a real benefit of vitamin D, for several reasons: If people in the placebo group decide on their own to take vitamin D supplements, that could minimize any differences between the placebo group and the supplement group; the study may not follow participants for a long enough time to show a cancer prevention benefit; or study participants may be starting supplements too late in life to lower their cancer risk. In the meantime, based on the evidence to date, 16 scientists have circulated a “call for action” on vitamin D and cancer prevention: (27) Given the high rates of vitamin D deficiency in North America, the strong evidence for reduction of osteoporosis and fractures, the potential cancer-fighting benefits of vitamin D, and the low risk of vitamin D supplementation, they recommend widespread vitamin D supplementation of 2000 IU per day. (27)

    Read more: vitamin D trials for cancer prevention

    [paste:font size="4"]39) The study didn’t find this effect among black men and women, most likely because there were fewer black study participants and most of them had low vitamin D levels, making it harder to find any link between vitamin D and MS if one exists.

    40) Evidence that vitamin D may play a role in preventing type 1 diabetes comes from a 30-year study that followed more than 10,000 Finnish children from birth: Children who regularly received vitamin D supplements during infancy had a nearly 90 percent lower risk of developing type 1 diabetes than those who did not receive supplements. (41) Other European case-control studies, when analyzed together, also suggest that vitamin D may help protect against type 1 diabetes. (42) No randomized controlled trials have tested this notion, and it is not clear that they would be possible to conduct.

    43) More than 20 years after this initial hypothesis, several scientists published a paper suggesting that vitamin D may be the seasonal stimulus. (44) Among the evidence they cite:

    • Vitamin D levels are lowest in the winter months. (44)
    • The active form of vitamin D tempers the damaging inflammatory response of some white blood cells, while it also boosts immune cells’ production of microbe-fighting proteins. (44)
    • Children who have vitamin D-deficiency rickets are more likely to get respiratory infections, while children exposed to sunlight seem to have fewer respiratory infections. (44)
    • Adults who have low vitamin D levels are more likely to report having had a recent cough, cold, or upper respiratory tract infection. (45)
    A recent randomized controlled trial in Japanese school children tested whether taking daily vitamin D supplements would prevent seasonal flu. (46) The trial followed nearly 340 children for four months during the height of the winter flu season. Half of the study participants received pills that contained 1,200 IU of vitamin D; the other half received placebo pills. Researchers found that type A influenza rates in the vitamin D group were about 40 percent lower than in the placebo group; there was no significant difference in type B influenza rates. This was a small but promising study, and more research is needed before we can definitively say that vitamin D protects against the flu. But don’t skip your flu shot, even if vitamin D has some benefit.

    47) More recent research suggests that the “sunshine vitamin” may be linked to TB risk. Several case-control studies, when analyzed together, suggest that people diagnosed with tuberculosis have lower vitamin D levels than healthy people of similar age and other characteristics. (48) Such studies do not follow individuals over time, so they cannot tell us whether vitamin D deficiency led to the increased TB risk or whether taking vitamin D supplements would prevent TB. There are also genetic differences in the receptor that binds vitamin D, and these differences may influence TB risk. (49) Again, more research is needed. (49)

    [paste:font size="4"]50) The analysis looked at the findings from 18 randomized controlled trials that enrolled a total of nearly 60,000 study participants; most of the study participants took between 400 and 800 IU of vitamin D per day for an average of five years. Keep in mind that this analysis has several limitations, chief among them the fact that the studies it included were not designed to explore mortality in general, or explore specific causes of death. More research is needed before any broad claims can be made about vitamin D and mortality. (51)
  6. BBC3

    BBC3 Member

  7. BBC3

    BBC3 Member

    The absorption and metabolism of vitamin D is comparable among Caucasian and African American women, according to new research published in the Journal of Clinical Endocrinology & Metabolism.

    There is a well known disparity gap in vitamin D levels between different ethnicities. For example, in a CDC report last year, 65% of African Americans were deficient in vitamin D compared to just 20% of Caucasians. While it is presumed that skin color plays the largest and perhaps sole hand in this gap (the darker the skin, the more sun exposure needed to make vitamin D), researchers still wanted to know, might different ethnicities absorb or metabolize vitamin D differently?

    If so, there would be big implications in setting recommended daily allowances in the future.

    In this study, Professor J Christopher Gallagher, MD, from Creighton University School of Medicine in Omaha, Nebraska, and colleagues investigated this topic.

    They measured vitamin D levels in 110 post-menopausal African American women aged 57-90 with vitamin D levels of 20 ng/ml or less. The women were randomized to receive a placebo or vitamin D supplement at 1 of 8 dose levels, ranging from 400 IU to 4,800 IU, for 1 year.

    The authors compared the results of the present study with a parallel study examining vitamin D metabolism in Caucasian women. Vitamin D status at baseline was lower in the African American participants compared to the Caucasian participants (13 ng/ml vs 17 ng/ml respectively). They found that the increase in serum vitamin D after supplementation in African American women was similar to that seen in the Caucasian women.

    Furthermore, 97.5% of women on 800 IU/daily – the RDA set by the IOM for elderly – from both the African American and Caucasian groups reached a level of 20 ng/ml.

    The researchers did not report what dose it took for the African American women to reach a level of 30 ng/ml and how that compared to the Caucasian women. It is reasonable to assume that since African Americans had lower baseline levels, that they would need a bigger dose than Caucasian women to ensure 97.5% of the population reached a 30 ng/ml threshold.

    However, for the time being, it looks as though vitamin D is absorbed and metabolized the same in both Caucasians and African Americans.

    The authors conclude,

    “The implication therefore is that the absorption and metabolism of vitamin D are similar in African American and Caucasian women. Although serum levels of serum 25OHD are usually much lower in African Americans, it is most likely because of decreased formation of vitamin D in skin.”


    Gallagher JC, Peacock M, Yalamanchili V, Smith LM. Effects of vitamin D supplementation in older African American women. J Clin Endocrin Metab. February 5, 2013.

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    vitamin d supplementation
    3 Responses to Are vitamin D supplement needs similar in Caucasian & African American women?
    1. [​IMG] Rita and Misty says:
      February 14, 2013 at 10:49 am

      Thank you for posting on this very important issue!

      I’ve commented before regarding Vitamin D deficiency within the African American population being a very serious problem.

      We in the Vitamin D Community know that recent research indicates that Vitamin D’s role in the body extends far greater than simply the prevention of rickets, osteomalacia and osteoporosis. Achieving and maintaining an adequate 25(OH)D level is essential to the prevention and treatment of autoimmune diseases such as MS and type 1 diabetes.

      Vitamin D also plays a protective role in cardiovascular health, various types of cancer, autism, depression, and schizophrenia, and respiratory conditions such as cystic fibrosis. The number of health conditions positively influenced by maintaining adequate levels of Vitamin D seems to increase daily.

      Because of our indoor lifestyles, Vitamin D deficiency is at epidemic proportions in the United States…actually worldwide. And it is worse among those with darker skin pigmentation, as melanin factors greatly into Vitamin D production.

      As I have mentioned before: the sunlight needs for people with darker skin pigmentation, living at higher latitudes, are immense and are not being met.

      A lighter pigmented person standing in full sun can produce a day’s bodily requirement of Vitamin D in about 15 minutes. In stark contrast, a person with darker skin pigmentation, standing in the same spot, will need approximately 6 times more sun exposure to produce the same amount of vitamin D. The following link will provide you with a thorough explanation:

      According to reports by the United States Center for Disease Control and Prevention, African American suffer greatly from chronic diseases such as cancer, heart disease, fibromyalgia, lupus, and obesity which can be effectively controlled or prevented with vitamin D supplementation.

      Unfortunately, many African Americans do not know about the health enhancing properties of vitamin D so their health continues to deteriorate.

      Despite the alarming health situation for Blacks, conventional medical practitioners do not seem to be informing Black people that they may need to take at least 5,000 IU of vitamin D3, in supplement form, every day; and that Black children should also be given adequate amounts of vitamin D3 on a daily basis, because food and drinks do not supply adequate amounts of vitamin D.

      Instead, all of us continue to be overloaded with prescription medications that treat the symptoms of illnesses while the causative factors are left unaddressed.

      Certainly Vitamin D deficiency is a serious problem for all of us…a pandemic…however, those with skin level VI have even greater deficiencies currently…and as informed members of the Vitamin D Community we have a responsibility to outreach and the time is now.

      Here you will find additional information:

      “…researchers Alan Peiris of East Tennessee State University and William Grant of the Sunlight, Nutrition and Health Research Center in San Francisco set out to look for a correlation between vitamin D and cancer death disparities. (In past research, Grant and a colleague suggested low levels of ultraviolet-B rays in Austria, paired with Mozart’s nocturnal habits, may have led to vitamin D deficiency in the composer, who died at the age of 35.)
      What they found in the new study is preliminary but warrants further investigation, they said. Relying solely on a scientific literature review, the researchers found that low vitamin D is independently associated with each of the cancer types for which an unexplained health disparity exists between African-Americans and white Americans.
      Specifically, they found lingering disparities for 13 types of cancer after accounting for socioeconomic status, stage at diagnosis, and treatment: bladder, breast, colon, endometrial, lung, ovarian, pancreatic, prostate, rectal, testicular, and vaginal cancer; Hodgkin’s lymphoma; and melanoma. For each one, there is a vitamin-D connection.
      Few scientific studies have directly explored the link between cancer deaths and low vitamin D levels in African-Americans, though. One study published in the journal Cancer in 2011 indeed found that vitamin D deficiency contributes to excess African-American mortality from colon cancer. A Harvard study published in Cancer Epidemiology, Biomarkers and Prevention in 2006 found that African-Americans who are at risk for low vitamin D also had a higher risk for cancer death, particularly for digestive-system cancers.
      The paucity of studies makes this a ripe topic for exploration, said Grant. If low vitamin D is the cause of this disparity in cancer deaths, thousands of lives could be saved annually by encouraging African-Americans to take a daily vitamin D supplement in the range of 1,000 to 4,000 IUs, he said.”
  8. BBC3

    BBC3 Member

    Controversy to my presentation...

    * This study is "newer" note, however, I believe it is a fine example of where SERUM SNAP SHOTS might actually prove GROSS ANOMALIES. And for once. You can denote as well that if Vit D is important to skeletal bone health, THEN WHAT ELSE IS SUFFERING if the bones come first. (Heart, etc..)..!!!!!!

    By the current blood test for vitamin D, most African-Americans are deficient. That can lead to weak bones. So many doctors prescribe supplement pills to bring their levels up.

    But the problem is with the test, not the patients, according to a new study. The vast majority of African-Americans have plenty of the form of vitamin D that counts — the type their cells can readily use.

    The research resolves a long-standing paradox.

    "The population in the United States with the best bone health happens to be the African-American population," says Dr. Ravi Thadhani, a professor of medicine at Massachusetts General Hospital and lead author of the study. "But almost 80 percent of these individuals are defined as having vitamin D deficiency. This was perplexing."

    The origin of this paradox is a fascinating tale of genes interacting with geography. More on that later.

    To unravel the mystery, Thadhani and his colleagues looked closely at various forms of vitamin D in the blood of 2,085 Baltimore residents, black and white. They focused on a form of the vitamin called 25-hydroxyvitamin D, which makes up most of the vitamin circulating in the blood. It's the form that the standard test measures.

    The 25-hydroxy form is tightly bound to a protein, and as a result, bone cells, immune cells and other tissues that need vitamin D can't take it up. It has to be converted by the kidneys into a form called 1,25-dihydroxyvitamin D.

    For Caucasians, blood levels of 25-hydroxyvitamin D are a pretty good proxy for how much of the bioavailable vitamin they have. But not for blacks.

    Medical Panel: Don't Go Overboard On Vitamin D

    That's because blacks have only a quarter to a third as much of the binding protein, Thadhani says. So the blood test for the 25-hydroxy form is misleading. His study finds that because of those lower levels of the protein, blacks still have enough of the bioavailable vitamin, which explains why their bones look strong even though the usual blood tests say they shouldn't.

    "The conclusion from this study is that just because your total levels are low, it doesn't mean we need to replace vitamin D" using supplements, Thadhani says. The study was published Wednesday in the New England Journal of Medicine.

    The reason people of African descent have far less protein-bound vitamin D is probably related to the geographic origins of the human race. Our earliest ancestors lived near the equator in Africa, where sunlight was plentiful and intense year-round.

    Vitamin D is synthesized in the skin when sunlight strikes it. When sunlight is deficient, the vitamin has to come from dietary sources such as eggs and fish oil.

    Fewer Americans Need Vitamin D Supplements Under New Guidelines

    Humans living in sunny climates make plenty of vitamin D on their own. In fact, one reason for the high degree of skin pigmentation in people of African descent is to prevent the synthesis of too much vitamin D, which can be toxic.

    Early humans didn't need to store up reserves of vitamin D, so they didn't need as much of the binding protein, whose function is to squirrel the vitamin away in a form where it can be used later.

    "Everyone who came out of Africa had the ancestral genotype associated with lower vitamin D-binding proteins," Thadhani says. "When humans moved to areas with less sunlight, a different genotype evolved. The further north they went, the more people needed reserves of vitamin D. So D-binding protein levels went up."

    And that genetic difference in vitamin D-binding proteins is what researchers have finally figured out.

    Study Hints Vitamin D Might Help Curb High Blood Pressure

    Dr. Michael Holick, a leading authority on vitamin D at Boston University Medical School, tells Shots that the new research is prompting him to resurrect blood samples from earlier studies to figure out whether the ill effects of low vitamin D in African-Americans and Caucasians are related to low levels of the bioavailable form or the protein-bound form.

    While the effect of vitamin D on bone health is undisputed, Holick says, "there's a lot of controversy about [the vitamin's effect on] hypertension, diabetes, cancer and infectious diseases."

    Meanwhile Holick, who wrote an editorial in the journal accompanying Thadhani's study, intends to keep giving his African-American patients vitamin D supplements when their blood levels of 25-hydroxyvitamin D are low, even though they may not need the pills to maintain strong bones.

    "There's no downside to supplementation, so it's not a big deal," Holick says.

    But Thadhani says doctors should hold off on prescribing vitamin D until they do other tests to determine whether their African-American patients are really vitamin D deficient. Those tests include blood levels of calcium, bone density tests andparathyroid hormone levels.

    There is currently no approved test for the bioavailable 1,25-dihydroxyvitamin D, although Thadhani and his colleagues are working on one and have filed for a patent.

    He says he used to take vitamin D supplements "until I realized there are genetic differences, then I stopped. I've looked at my bioavailable levels of vitamin D. Now I'm comforted to know that I'm not deficient."
  9. BBC3

    BBC3 Member

    The evidence GOES ON AND ON AND ON.. But far be it from medical science to use COMMON SENSE. I do not think they possess.... FUNNY HOW EVEN ON TRT, my training reginmen REALLY EXCELLS ONLY in the summer time when I am catching rays...!

    I think Sutherlands only NICE ROLE, before he became the supervillain in every flick there forward.. LOL

  10. Michael Scally MD

    Michael Scally MD Doctor of Medicine

    Melhem SJ, Aiedeh KM, Hadidi KA. Effects of a 10-day course of a high dose calciferol versus a single mega dose of ergocalciferol in correcting vitamin D deficiency. Ann Saudi Med. 2015;35(1):13-8.

    BACKGROUND AND OBJECTIVES: The correction of vitamin D deficiency is crucial for optimal skeletal and non-skeletal health. Most regimens in current use are based on daily dosing, which may raise concerns of dosage inadequacy and suboptimal patient compliance.

    Vitamin D is available in 2 forms: D2 (ergocalciferol) and D3 (cholecalciferol).

    It has been reported that D2 supplements are less effective and may enhance the degradation of 25-hydroxyvitamin D3 (25[OH]D3) metabolite.

    The aim of this study was to compare the effect of 2 high-dose oral vitamin D regimens-a 10-day course of D3 500000 IU versus a single mega dose of 600000 IU D2-on serum 25(OH)D levels.

    DESIGN AND SETTINGS: A prospective cohort study was conducted from September 2010 to February 2011 in an urban university tertiary hospital in Amman, Jordan.

    PATIENTS AND METHODS: A total of 109 patients aged 18 to 79 years were enrolled with severe vitamin D deficiency.

    Fifty-one subjects received 600000 IU D2 orally and 54 subjects received a total dose of 500000 IU D3 administered orally, as 50000 IU D3 daily for 10 consecutive days. Baseline and follow-up total serum 25(OH)D, 25(OH)D2, and 25(OH)D3 levels were compared.

    RESULTS: The mean total 25(OH)D increment from baseline was 10.33 (5.68) ng/mL over a mean of 43.08 (2.81) days for the D2 group.

    The mean increment in 25(OH)D for the D3 group was 47.03 (23.67) ng/mL over a mean of 36.9 (2.9) days.

    The difference between the 2 mean increments was highly significant: P=3.15.10-18. The 600 000 IU D2 single mega-dose decreased 25(OH)D3 levels by an average of 4 ng/mL in 37 subjects.

    CONCLUSION: Overall, the 10-day oral D3 regimen rapidly and effectively normalized 25(OH)D levels. The shortened dosing interval over 10 consecutive days might result in higher compliance.
  11. Michael Scally MD

    Michael Scally MD Doctor of Medicine

    Wang N, Han B, Li Q, Chen Y, Chen Y, et al. Vitamin D is associated with testosterone and hypogonadism in Chinese men: Results from a cross-sectional SPECT-China study. Reprod Biol Endocrinol. 2015;13(1):74.

    BACKGROUND: To date, no study has explored the association between androgen levels and 25-hydroxyvitamin D (25(OH)D) levels in Chinese men. We aimed to investigate the relationship between 25(OH)D levels and total and free testosterone (T), sex hormone binding globulin (SHBG), estradiol, and hypogonadism in Chinese men.

    METHODS: Our data, which were based on the population, were collected from 16 sites in East China. There were 2,854 men enrolled in the study, with a mean (SD) age of 53.0 (13.5) years. Hypogonadism was defined as total T <11.3 nmol/L or free T <22.56 pmol/L.

    The 25(OH)D, follicle-stimulating hormone, luteinizing hormone, total T, estradiol and SHBG were measured using chemiluminescence and free T by enzyme-linked immune-sorbent assay.

    The associations between 25(OH)D and reproductive hormones and hypogonadism were analyzed using linear regression and binary logistic regression analyses, respectively.

    RESULTS: A total of 713 (25.0 %) men had hypogonadism with significantly lower 25(OH)D levels but greater BMI and HOMA-IR.

    Using linear regression, after fully adjusting for age, residence area, economic status, smoking, BMI, HOMA-IR, diabetes and systolic pressure, 25(OH)D was associated with total T and estradiol (P < 0.05). In the logistic regression analyses, increased quartiles of 25(OH)D were associated with significantly decreased odds ratios of hypogonadism (P for trend <0.01).

    This association, which was considerably attenuated by BMI and HOMA-IR, persisted in the fully adjusted model (P for trend <0.01) in which for the lowest compared with the highest quartile of 25(OH)D, the odds ratio of hypogonadism was 1.50 (95 % CI, 1.14, 1.97).

    CONCLUSIONS: A lower vitamin D level was associated with a higher prevalence of hypogonadism in Chinese men. This association might, in part, be explained by adiposity and insulin resistance and warrants additional investigation.
  12. roastdawg

    roastdawg Member

    A bit of anecdotal evidence, I normally catch every cold that comes around. Since I started supplementing vit d about ten months ago I haven't been sick once. We'll see if it's just a lucky stretch or if there's something to it.
    retpsd likes this.
  13. slashlove

    slashlove Member

    nice posts here guys ;)

    "Pain is temporary, Pride is forever»
  14. retpsd

    retpsd Member

    Same here dawg, same here!
    roastdawg likes this.
  15. LW64

    LW64 Member

    Try nearly seven years on for size, ok?

    I began supplementing in the Fall of 2008 and have not had a cold since then.
    roastdawg likes this.
  16. nickley

    nickley Junior Member

    Nice post on Vitamin D. I think it is a very important vitamin for the proper functioning of our cells in the muscles, heart and other organs. Do you know sitting under the sun in the morning can get you some vitamin D? Correct me if i'm wrong!
  17. Michael Scally MD

    Michael Scally MD Doctor of Medicine

    Scholten SD, Sergeev IN, Song Q, Birger CB. Effects of vitamin D and quercetin, alone and in combination, on cardiorespiratory fitness and muscle function in physically active male adults. Open Access J Sports Med. 2015;6:229-39.

    INTRODUCTION: Vitamin D and the antioxidant quercetin, are promising agents for improving physical performance because of their possible beneficial effects on muscular strength and cardiorespiratory fitness.

    PURPOSE: The purpose of this study was to determine the effects of increased intakes of vitamin D, quercetin, and their combination on antioxidant status, the steroid hormone regulators of muscle function, and measures of physical performance in apparently healthy male adults engaged in moderate-to-vigorous-intensity exercise training.

    METHODS: A total of 40 adult male participants were randomized to either 4,000 IU vitamin D/d, 1,000 mg/d quercetin, vitamin D plus quercetin, or placebo for 8 weeks. Measures of cardiorespiratory fitness and muscle function, blood markers for antioxidant and vitamin D status, and hormones 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and testosterone were measured pre- and postsupplementation.

    RESULTS: At enrollment, 88.6% of participants were vitamin D sufficient (serum 25-hydroxyvitamin D >50 nmol/L) and had normal serum testosterone levels.

    Supplementation with vitamin D significantly increased serum 25(OH)D concentration (by 87.3% in the vitamin D group, P<0.001) and was ASSOCIATED WITH AN INCREASING TREND OF TESTOSTERONE CONCENTRATION.

    There were no changes in concentration of 1,25(OH)2D3 and markers of antioxidant status associated with vitamin D or quercetin supplementation. No improvements in physical performance measures associated with vitamin D and quercetin supplementation were found.

    CONCLUSION: The findings obtained demonstrate that long-term vitamin D and quercetin supplementation, alone or in combination, does not improve physical performance in male adults with adequate vitamin D, testosterone, and antioxidant status.
    heady muscle likes this.
  18. Michael Scally MD

    Michael Scally MD Doctor of Medicine

    [Open Access] Plausible Ergogenic Effects of Vitamin D on Athletic Performance and Recovery

    Dahlquist DT, Dieter BP, Koehle MS. Plausible ergogenic effects of vitamin D on athletic performance and recovery. J Int Soc Sports Nutr. 2015;12:33.

    The purpose of this review is to examine vitamin D in the context of sport nutrition and its potential role in optimizing athletic performance.

    Vitamin D receptors (VDR) and vitamin D response elements (VDREs) are located in almost every tissue within the human body including skeletal muscle.

    The hormonally-active form of vitamin D, 1,25-dihydroxyvitamin D, has been shown to play critical roles in the human body and regulates over 900 gene variants.

    Based on the literature presented, it is plausible that vitamin D levels above the normal reference range (up to 100 nmol/L) might increase skeletal muscle function, decrease recovery time from training, increase both force and power production, and increase testosterone production, each of which could potentiate athletic performance.

    Therefore, maintaining higher levels of vitamin D could prove beneficial for athletic performance. Despite this situation, large portions of athletic populations are vitamin D deficient.

    Currently, the research is inconclusive with regards to the optimal intake of vitamin D, the specific forms of vitamin D one should ingest, and the distinct nutrient-nutrient interactions of vitamin D with vitamin K that affect arterial calcification and hypervitaminosis.

    Furthermore, it is possible that dosages exceeding the recommendations for vitamin D (i.e. dosages up to 4000-5000 IU/day), in combination with 50 to 1000 mcg/day of vitamin K1 and K2 could aid athletic performance.

    This review will investigate these topics, and specifically their relevance to athletic performance.

  19. Michael Scally MD

    Michael Scally MD Doctor of Medicine

    Caretta N, Vigili de Kreutzenberg S, Valente U, Guarneri G, Pizzol D, et al. Hypovitaminosis D is associated with lower urinary tract symptoms and benign prostate hyperplasia in type 2 diabetes. Andrology.

    Lower urinary tract symptoms (LUTS) may develop more commonly in men with type 2 diabetes mellitus (T2DM). LUTS are often associated with benign prostate hyperplasia (BPH), in general population.

    An association between LUTS and hypovitaminosis D, and between hypovitaminosis D and type 2 diabetes (T2DM), has also been suggested. Thus, we aim to evaluate possible relationships between hypovitaminosis D, LUTS, and BPH in T2DM men.

    In this prospective observational study, 67 T2DM males (57.9 +/- 9.28 years) underwent medical history collection, International Prostate Symptom Score (IPSS) questionnaire, that allows the identification and grading of LUTS, physical examination, biochemical/hormonal blood tests (fasting plasma glucose, glycated haemoglobin, total cholesterol, high-density lipoprotein cholesterol, triglycerides, creatinine, LH, total testosterone, estradiol (E2 ), 25-OH-vitamin D, PTH, calcium, phosphate, and PSA) and ultrasound transrectal prostate examination.

    Subdividing patients into three groups, on the base of 25-OH-vitamin D concentration (sufficiency >/=50; insufficiency >25 < 50; and deficiency </=25 nm), a significant progressive increase of prostate volume (p = 0.037), IPSS score (p = 0.019), diastolic blood pressure (p = 0.018), and a significant decrease in HDL cholesterol (p = 0.038) were observed. 25-OH-Vitamin D levels were inversely correlated with both IPSS (R = -0.333; p = 0.006) and prostate volume (R = -0.311; p = 0.011). At multivariate analysis, hypovitaminosis D remained an independent predictor of both IPSS and prostate volume.

    In conclusion, we showed, for the first time, an association between 25-OH-vitamin D deficiency, LUTS, and BPH in T2DM men.