Sunday, May 24, 2009
Vitamin D: Disease Prevention
Image: courtesy of grassrootshealth.org (and imminst.org)
Cancer and Vitamin D
Few prospective vitamin D trials exist in the literature in humans for cancer. Our best data exists as epidemiological observations. The above wonderful graphic depiction of the relationship between disease prevention and serum concentrations of vitamin D [25OHD] was complied by grassrootshealth.org. Dr. Davis attended a conference last year and learned that the NIH budget for studying cancer and vitamin D will be increased by $200 million. Heartening to know that funding is being put to actually good use. Cancer has now superceded heart disease to take the #1 spot for mortality in the U.S. Hopefully we'll learn more in a decade or a two! I believe it is difficult to expect Pharma or other large deep-pocketed research giants (backed by lobbyists) to fund a trial where the preventive treatment (OTC at Trader Joe's or Walmart or Target or Costco or iHerb.com) costs as little as $2 per month and prevents a $150,000+++ cancer treatment paid for by Medicare and most insurance companies.
In the meantime...can you afford to wait for the research results?
Hopefully NIH scientists will 'get it right'... and...
(1) Use the therapeutic doses of vitamin D 4000-8000 IU daily (not 400-800 IU daily which are literally doses recommended for babies, infants and toddlers by the Academy of Pediatrics),
(2) Use vitamin D3 (not synthetic D2 which is not metabolized well by majority of the globe, esp Indo-Asians, and is linked to toxicity compared to natural D3)
(3) Use 'tracking' of [25OHD] blood concentrations
(4) Use results where [25OHD] is greater than 50 ng/ml (not just greater than 30 ng/ml... see above graph). [25OHD] of 30 ng/ml accomplishes nearly N O T H I N G... except rickets prevention greater than 99%.
Don't you deserve greater than 35%, 83%, 17%, 60%, 18%, 66%, 50%, 72%, 54%, 30%, 49%, 37% prevention, respectively for the cancers and conditions listed above?
And your family and friends?
Vitamin D, Safety and Dosing
Dosing depends on a variety of factors. You really don't know if you have the right dose unless you check 4-6 wks after initiating supplementation. Everyone is uniquely different and so are the enzymes which activate and de-activate vitamin D and its derivatives, the skin protective melanin/pigmentation which blocks excessive activation, how much time spent indoors, how much makeup/sunscreen/clothes are worn, etc.
Dr. Cannell, Dr. Davis and other vitamin D experts advise starting at vitamin D3 5,000 IU daily in the morning/daytime if you receive no sunlight or live in an area devoid of UVB radiation (~half of the year nearly zero UVB above the 37th latitude).
The below graph is from a prominent vitamin D researcher, Dr. Vieth, in Canada where vitamin D supplementation is nearly mandatory (Vieth R 1999). I've superimposed the dose I take to achieve 60 - 70 ng/ml, vitamin D 5,000 IU daily. In winter I take 8,000 to 10,000 IU daily which is more similar to the dosing curve Vieth has determined in his clinical research.
For U.S. standard lab values, to convert nmol/L to ng/ml, divide by 2.5.
Dr. Vieth writes that "The clinical trial evidence shows that a prolonged intake of 250 mug (10,000 IU)/d of vitamin D(3) is likely to pose no risk of adverse effects in almost all individuals in the general population; this meets the criteria for a tolerable upper intake level (Vieth R 2007)."
Dose response for vitamin D intake versus final serum 25-hydroxyvitamin D [25(OH)D] concentration reported. Circles indicate group means from Tables 4 and 5. Points indicated by "X" represent single values from Table 5 for people reported as intoxicated with vitamin D. The arrow indicates the lowest dose reported as causing hypercalcemia, but which is an outlier because vitamin D was given as a single dose of 7500 µg (300000 IU)/mo, instead of 250 µg (10000 IU)/d (77). If authors reported 25(OH)D for several time points, only the final serum 25(OH)D is shown in the figure. The line representing the dose response passes through the points that represent group data.
Low wintertime vitamin D levels in a sample of healthy young adults of diverse ancestry living in the Toronto area: associations with vitamin D intake and skin pigmentation.
Gozdzik A, Barta JL, Wu H, Wagner D, Cole DE, Vieth R, Whiting S, Parra EJ.
BMC Public Health. 2008 Sep 26;8:336.
Vitamin D from dietary intake and sunlight exposure and the risk of hormone-receptor-defined breast cancer.
Blackmore KM, Lesosky M, Barnett H, Raboud JM, Vieth R, Knight JA.
Am J Epidemiol. 2008 Oct 15;168(8):915-24. Epub 2008 Aug 27.
Evidence for genetic regulation of vitamin D status in twins with multiple sclerosis.
Orton SM, Morris AP, Herrera BM, Ramagopalan SV, Lincoln MR, Chao MJ, Vieth R, Sadovnick AD, Ebers GC.
Am J Clin Nutr. 2008 Aug;88(2):441-7.
Vitamin D toxicity, policy, and science.
J Bone Miner Res. 2007 Dec;22 Suppl 2:V64-8. Review.
Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety.
Vieth R. PDF here.
Am J Clin Nutr. 1999 May;69(5):842-56. Review.