"June 29, 2009 | Shelley Wood
Boston, MA - A massive, National Institutes of Health-sponsored study looking at whether vitamin-D and/or omega-3 fatty-acid supplementation can reduce the risk of developing heart disease, stroke, or cancer will get under way in January 2010, according to a website for the study. Drs JoAnn Manson and Julie Buring (Harvard Medical School/ Brigham and Women's Hospital, Boston, MA) will head up the Vitamin D and Omega-3 Trial (VITAL).
The study is aiming to enroll 20 000 men and women, one-quarter of whom will be black. According to a Brigham and Women's Hospital press release, the study is intentionally aiming to illuminate a potential racial and ethnic disparity hypothesized to be linked to vitamin D [1]. "African Americans have a higher risk of vitamin-D deficiency as well as a greater frequency of diabetes, hypertension, and certain types of cancer," a press release notes. For VITAL, women need to be over age 65 to enter the study; men need to be over age 60.
Study participants will be randomized to one of four groups: daily vitamin D (2000 IU) and fish oil (1 g); daily vitamin D and fish-oil placebo; daily vitamin-D placebo and fish oil; or daily vitamin-D placebo and fish-oil placebo. The trial will run for five years and is expected to cost US $20 million."
"From 1955 to 1990, all infants in East Germany received 600,000 IU of Vitamin D every three months for a total of 3,600,000 IU at age 18 months.
With the 400 IU/day recommendation of the American Pediatric Association in mind, I ran across this amazing paper while surfing Medline for Vitamin D. According to this paper, all infants in the German Democratic Republic (East Germany) received dangerously high doses of Vitamin D every three months in their doctors office. The policy was in place for 35 years. The first 600,000 IU dose was given at three months and then every three months until the child was 18 months of age. This works out to an average of 6,000 IU per day (actually, for several technical reasons it is not equivalent) for 18 months. The authors collected blood before the dose and then 2 weeks after the quarterly dose to obtain 25(OH)D, 1,25(OH)D, and calcium levels on a total of 43 infants.
Before the first dose, at 3 months of age, the average infant was extremely deficient (median 25(OH)D of 7 ng/ml). Two weeks after the first dose the average 25(OH)D level was 120 ng/ml, the second dose 170 ng/ml, the third dose, 180 ng/ml, the fourth dose, 144 ng/ml, the fifth dose, 110 ng/ml and after the sixth and final dose, 3.6 million total units, at age 18 months, the children had mean levels of 100 ng/ml. That is, by the 15 and 18 month doses, the children were beginning to effectively handle these massive doses.
The highest level recorded in any of the 43 infants was 408 ng/ml at age 9 months, two weeks after the third 600,000 IU dose. Thirty-four percent of the infants had at least one episode of hypercalcemia but only 3 had an elevated serum 1,25(OH)D. The authors reported that all the infants appeared healthy, even the infant with a level of 408 ng/ml, that is, no clinical toxicity was noted in any of these infants."
This month, the authoritative International Agency for Research into Cancer (IARC) have weighed in on the issue. By gathering a group of expert scientists, they have looked at all the available evidence and published a detailed report on vitamin D and cancer. The massive tome weighs in at 465 pages, but we'll take a look at the key points in the first of two posts looking at the vitamin D debate.
It is impossible for us to get more than about five percent of the vitamin D we need from our diet - unless, like Eskimos, we eat oily fish three times a day.