Take Vitamin D, Live Longer?

(WebMD)  Taking vitamin D supplements may help people live longer, according to a new research review. But it's not yet clear exactly how vitamin D does that.

The new review, published in the Archives of Internal Medicine, comes at a time when vitamin D is a hot topic linked to benefits including lower risk of some cancers and fewer falls for elders.

The body makes vitamin D when exposed to sunshine. Vitamin D is also found in some foods, including salmon, and in some fortified foods, including some dairy products and cereals.

But some experts are concerned that vitamin D deficiency is too common and suggest that the current recommended intake of vitamin D is too low.

The new vitamin D review comes from Philippe Autier, MD, and Sara Gandini, PhD.

Autier works for the International Agency of Research on Cancer in Lyon, France. Gandini works for the European Institute of Oncology in Milan, Italy.

Together, they analyzed the results of 18 vitamin D studies that included mortality rates.

More than 57,000 adults in the United States, United Kingdom, and Europe participated in the studies. Most of them were "frail" elders with low blood levels of vitamin D, write Autier and Gandini.

Participants were typically assigned to take vitamin D supplements or a placebo containing no vitamin D.

Their daily vitamin D doses ranged from 300 to 2,000 international units (IU), averaging 528 IU per day, in the form of ergocalciferol (vitamin D-2) or cholecalciferol (vitamin D-3).

Each study was designed differently, but on average, participants were followed for 5.7 years. During that time, 4,777 participants died of any cause.

People taking vitamin D were 7 percent less likely to die during the studies. The precise reason for their lower death rate isn't clear, and the reviewers aren't recommending a specific vitamin D dose.

An editorial published with the study recommends more research on vitamin D's benefits.

"The roles of moderate sun exposure, food fortification with vitamin D, and higher-dose vitamin D supplements for adults need to be debated," writes editorialist Edward Giovannucci, MD, who works in Harvard School of Public Health's nutrition department.

By Miranda Hitti
Reviewed by Louise Chang
©2007 WebMD, Inc. All rights reserved

[tedhutchinso]

"Risk Assessment for Vitamin D" shows 10,000iu daily to be a safe upper limit. Hypercalcemia occurs only after 40,000iu daily has been taken for many months and the nmol/l level has exceeded 375nmol/L.

"Safety of vitamin D3 in adults with multiple sclerosis." shows how 280,000iu/wk for 28 weeks produced no ill effects.

"The urgent need to recommend an intake of vitamin D that is effective" shows that 400iu/daily raises status by around 9nmol/L.

Most UK adults have levels around 40nmol/L during the Winter so to raise their status to around the level required for lowest cancer incidence 137.5nmol/L will require considerable more than 1000iu daily.

Readers should also be aware of "The Case Against Ergocalciferol (Vitamin D2) as a Vitamin Supplement"

[bwessels]

This article needs to talk about Vitamin D toxicity in large doses, as well. Also, the FDA needs to get out there quickly with consensus recommended levels; it seems like nutrition labeling gets reviewed once every 20-25 years, which does not keep up with modern research at all.

[salty1954]

Most nutritionists recommend 1000 IU a day.