Vitamin D

"Women with fertility problems may benefit from taking vitamin D supplements, research has found. A study has found a link between low levels of Vitamin D and problems with ovulation. The research may offer a simple, cheap and safe option for women to try before resorting to drugs."

Athletic performance and vitamin D. Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ. Med Sci Sports Exerc. 2009 May;41(5):1102-10. Review. PMID: 19346976 doi: 10.1249/MSS.0b013e3181930c2b Conclusions: Vitamin D may improve athletic performance in vitamin D-deficient athletes. Peak athletic performance may occur when 25(OH)D levels approach those obtained by natural, full-body, summer sun exposure, which is at least 50 ng·mL-1. Such 25(OH)D levels may also protect the athlete from several acute and chronic medical conditions.

"So why is Dr Vieth so frustrated? You might think he'd have cause for celebration. But for him and other vitamin D researchers around the world, the good news comes with a bitter aftertaste. They believe they can prove vitamin D could help millions live longer and be healthier and yet they have not been able to convince their own governments. In the US and Canada, official vitamin D policy is set by the Institute of Medicine. And in the opinion of Vieth, the current recommendations - 200 International Units per day for people under 50, 400 for people aged 51-70, and 600 for those 71 and older - are outrageously low. Bruce Hollis, professor of paediatrics at the Medical University of South Carolina, calls 400 IU a day "a joke". That's because the best research suggests that to achieve the higher vitamin D blood levels associated with disease prevention, most adults in the US would need to take 1,000-2,000 IU a day: five to 10 times more than the current official recommendation for adult In 1999, Reinhold Vieth (pictured right) published a review of vitamin D research in response to the IOM conclusions. In it, he argued that there was no evidence that amounts lower than 20,000 IU a day could be toxic. "Throughout my preparation of this review, I was amazed at the lack of evidence supporting statements about the toxicity of moderate doses of vitamin D," Vieth wrote. Studies have since shown 10,000 IU a day of vitamin D to be safe. While any substance will become toxic in excess, vitamin D researchers today accept that the current vitamin D recommendations could be more than quadrupled with no fear of toxicity.!

Vitamin D supplementation reduces insulin resistance in South Asian women living in New Zealand who are insulin resistant and vitamin D deficient - a randomised, placebo-controlled trial. von Hurst PR, Stonehouse W, Coad J. Br J Nutr. 2009 Sep 28:1-7. [Epub ahead of print] PMID: 19781131 In conclusion, improving vitamin D status in insulin resistant women resulted in improved IR and sensitivity, but no change in insulin secretion. Optimal vitamin D concentrations for reducing IR were shown to be 80-119 nmol/l, providing further evidence for an increase in the recommended adequate levels. Registered Trial No. ACTRN12607000642482.

"Last Wednesday night I gave a lecture to my clients on hunter-gatherer diets. The turnout was great and the information was well-received. I had it professionally video-recorded and will probably offer this as a DVD for sale (with the handout included). Watch for it in the future. Part of what I discussed was vitamin D3 supplementation. Since I have been supplementing with 4,000-10,000 Units of D3 per day I have noted enhanced recovery and size response from my training. Apparently, skeletal muscle has both surface receptors and nuclear receptors for D3 that augment calcium flux during contraction (from surface receptors) and have steroid-like effects at the nuclear level WRT protein synthesis. This D3 supplementation is not really "supplementation" but is instead "augmentation" to levels that would be normal if we got normal sun exposure as we did in our evolutionary past. Check out www.vitamindcouncil.org for more information. Also, check out this abstract below for your consideration. Also, check out this article."

Onko D-vitamiini ihmelääke? Auringosta tai purkista saatavan supervitamiinin väitetään suojaavan syövältä, sydänsairauksilta, sikainfluenssalta, masennukselta ja auttavan jopa laihtumaan. Monet kokevat kaamosmasennuksen helpottavan, kun syövät riittävän korkeita määriä D-vitamiinia. Kuulostaa liian hyvältä ollakseen totta. Vanha tuttu D-vitamiini onkin yhtäkkiä kuin taikajuoma, joka auttaa melkein mihin tahansa. Se laihduttaa, ehkäisee syöpää, laskee verenpainetta, kohottaa mielialaa. Vitamiini tuntuu tekevän melkein mitä tahansa, kunhan se on positiivista. Uusista hyötyvaikutuksista kerrotaan päivittäin. Time-lehti julisti jo pari vuotta sitten D-vitamiinin saannin ja vaikutuksien selvittämisen yhdeksi tieteen tärkeimmistä tutkimuskohteista! "D-vitamiini on hyvä tietokilpailukysymys, kun kysytään, mihin sairauteen sen puute ei näytä jotenkin liittyvän", toteaa Jouni Karhu. Hänet tunnetaan verkkokeskusteluissa väsymättömästi D-vitamiinia suitsuttavana nimimerkki Neonomidena, jonka monipuolisten tietojen innoittamana monet ovat marssineet apteekin vitamiinihyllylle tai tilanneet D-pillereitä verkkokaupasta.

"Calbindin describes calcium binding proteins first described as the vitamin D-dependent calcium binding proteins in intestine and kidney."

"Vitamin D-dependent calcium binding proteins were discovered in the cytosolic fractions of chicken intestine, and later in mammalian intestine and kidney, by workers including Robert Wasserman of Cornell University. They bound calcium in the micromolar range and were greatly reduced in vitamin D-deficient animals. Expression could be induced by treating these animals with vitamin D metabolites such as calcitriol. They were found to exist in two distant sizes with a molecular weight of approximately 9 kDa and 28 kDa. They were renamed calbindin; calbindin-D9k is found in mammalian intestine and calbindin-D28k in avain intestine and in kidney."

"Numerous studies link Vitamin D and influenza, as well as Vitamin D and respiratory infections more generally. This vitamin up-regulates genetic expression of various endogenous antimicrobial peptides (AMP), which exhibit broad-spectrum microbicidal activity against bacteria, fungi, and viruses. Reports discussed below indicate that susceptibility to influenza is reduced with higher levels of sun exposure or vitamin D supplementation. Seasonal variation of vitamin D levels in humans can help explain the seasonality of flu epidemics."

"Ergocalciferol (Deltalin, Eli Lilly and Company) is a form of vitamin D, also called vitamin D2. It has the systematic name "(3β,5Z,7E,22E)-9,10-secoergosta-5,7,10(19),22-tetraen-3-ol". It is created from viosterol, which in turn is created when ultraviolet light activates ergosterol."

"Cholecalciferol is a form of Vitamin D, also called vitamin D3 or calciol.[1] It is structurally similar to steroids such as testosterone, cholesterol, and cortisol (though vitamin D3 itself is a secosteroid). One gram of pure vitamin D3 is 40 000 000 (40x106) IU, or, in other words, one IU is 0.025 μg. Individuals having a high risk of deficiency should consume 125 μg (5000 IU) of vitamin D daily"

"Cathelicidin antimicrobial peptide is a family of polypeptides found in lysosomes in polymorphonuclear leukocytes (PMNs).[1] Members of the cathelicidin family of antimicrobial polypeptides are characterized by a highly conserved region (cathelin domain) and a highly variable cathelicidin peptide domain. Cathelicidin peptides have been isolated from many different species of mammals. Cathelicidins were originally found in neutrophils but have since been found in many other cells including epithelial cells and macrophages activated by bacteria, viruses, fungi, or the hormone 1,25-D"

The vitamin D-antimicrobial peptide pathway and its role in protection against infection. Gombart AF. Future Microbiol. 2009 Nov;4:1151-65. PMID: 19895218 doi:10.2217/fmb.09.87

"If you're running low on vitamin D - as an estimated 70 percent of the U.S. population is - your immune system may not be functioning as well as it should. As a result, you may be more vulnerable to infectious diseases than you would if your vitamin D levels were optimal. Worse, you could be at higher than normal risk of a long list of diseases including heart disease and several kinds of cancer. A report recently published journal, Future Microbiology, highlighted research at the Linus Pauling Institute at Oregon State University, which has shown that vitamin D induces expression of an antimicrobial peptide gene called cathelicidin that is the "first line of defense" in the immune system's response to minor wounds, cuts and bacterial and viral infections. The regulation of cathelicidin by vitamin D could help explain its vital role in immune function. The report noted that vitamin D is a key cofactor in reducing inflammation, in blood pressure control and helping to protect against heart disease. Author Adrian Gombart explains that there is still much to explore about D's mechanisms of action, the potential use of synthetic analogs of it in new treatments, and its duty in fighting infection."

"Vitamin D, often referred to as the "sunshine vitamin," is actually a fat-soluble hormone that the body can synthesize naturally. There are several forms, including two that are important to humans: D2 and D3. Vitamin D2 (ergocalciferol) is synthesized by plants, and vitamin D3 (cholecalciferol) is synthesized by humans when skin is exposed to ultraviolet-B (UVB) rays from sunlight. The active form of the vitamin is calcitriol, synthesized from either D2 or D3 in the kidneys. Vitamin D helps to maintain normal blood levels of calcium and phosphorus"

Serum 25-Hydroxyvitamin D Levels Among US Children Aged 1 to 11 Years: Do Children Need More Vitamin D? Mansbach JM, Ginde AA, Camargo CA Jr. Pediatrics. 2009 Nov;124(5):1404-1410. PMID: 19951983 CONCLUSIONS: On the basis of a nationally representative sample of US children aged 1 to 11 years, millions of children may have suboptimal levels of 25(OH)D, especially non-Hispanic black and Hispanic children. More data in children are needed not only to understand better the health implications of specific serum levels of 25(OH)D but also to determine the appropriate vitamin D supplement requirements for children.

"Hypervitaminosis D is a state of vitamin D toxicity. The recommended daily allowance is 400 IU per day. Overdose has been observed at 1925 µg/d (77,000 IU per day). Acute overdose requires between 15,000 µg/d (600,000 IU per day) and 42,000 µg/d (1,680,000 IU per day) over a period of several days to months, with a safe intake level being 250 µg/d (10,000 IU per day).[1] Foods contain low levels, and have not been known to cause overdose. Overdose has occurred due to industrial accidents, for example when incorrectly formulated pills were sold or missing industrial concentrate cans misused as cans of milk. Vitamin D toxicity is unlikely except when certain medical conditions are present, such as primary hyperparathyroidism, sarcoidosis, tuberculosis, and lymphoma."

"Hypovitaminosis D is a deficiency of Vitamin D. It can result from: inadequate intake coupled with inadequate sunlight exposure (in particular sunlight with adequate ultra violet B rays), disorders that limit its absorption, conditions that impair conversion of vitamin D into active metabolites, such as liver or kidney disorders, or, rarely, by a number of hereditary disorders.[1] Deficiency results in impaired bone mineralization, and leads to bone softening diseases, rickets in children and osteomalacia in adults, and contributes to osteoporosis.[1] Osteomalacia may also occur rarely as a side-effect of phenytoin use Hypovitaminosis D is typically diagnosed by measuring the concentration in blood of the compound 25-hydroxyvitamin D (calcidiol), which is a precursor to the active form 1,25-dihydroxyvitamin D (calcitriol).[6] One recent review has proposed the following four categories for hypovitaminosis D:[7] * Insufficient 50-100 nmol/L (20-40 ng/mL) * Mild 25-50 nmol/L (10-20 ng/mL) * Moderate 12.5-25.0 nmol/L (5-10 ng/mL) * Severe < 12.5 nmol/L (< 5 ng/mL) Note that 1.0 nmol/L = 0.4 ng/mL for this compound.[8] Other authors have suggested that a 25-hydroxyvitamin D level of 75-80 nmol/L (30-32 ng/mL) may be sufficient

Vitamin D and mortality in older men and women. Pilz S, Dobnig H, Nijpels G, Heine RJ, Stehouwer CD, Snijder MB, van Dam RM, Dekker JM. Clin Endocrinol (Oxf). 2009 Nov;71(5):666-72. Epub 2009 Feb 18. PMID: 19226272 DOI: 10.1111/j.1365-2265.2009.03548.x Conclusions Low 25(OH)D levels are associated with all-cause mortality and even more pronounced with cardiovascular mortality, but it remains unclear whether vitamin D deficiency is a cause or a consequence of a poor health status. Therefore, intervention studies are warranted to evaluate whether vitamin D supplementation reduces mortality and cardiovascular diseases.

Low serum 25-hydroxyvitamin D concentrations are associated with greater all-cause mortality in older community-dwelling women. Semba RD, Houston DK, Ferrucci L, Cappola AR, Sun K, Guralnik JM, Fried LP. Nutr Res. 2009 Aug;29(8):525-30. PMID: 19761886 doi:10.1016/j.nutres.2009.07.007 Older community-dwelling women with low 25(OH)D levels are at an increased risk of death.