Early Research on Vitamin D
Men with low blood levels of vitamin D appear to have a higher risk of heart attack than those with adequate levels, according to research published in the Archives of Internal Medicine (June 9, 2008; 168(11):1174–1180). This nested case-control study included 18,225 men participating in the Health Professionals Follow-up Study. The men were between the ages of 40 and 75 and were free of diagnosed cardiovascular disease at the time blood samples were collected.
Over a 10-year follow-up period, 454 men experienced either a nonfatal myocardial infarction or fatal coronary heart disease. Men with serum vitamin D levels below 15 ng/mL were found to be 2.42 times more likely to experience a fatal or nonfatal coronary event compared to men with adequate vitamin D levels.
Additional research published in the Journal of the American Geriatrics Society (Volume 56, Issue 5, pp. 785–791) examined whether the relationship between pain and vitamin D status differed by sex. The study included 958 men and women over the age of 65. Among the participants, 58 percent of women and 27 percent of men reported at least moderate pain in the low back or lower extremities.
Serum vitamin D levels were measured, and low vitamin D status was strongly associated with low back pain in women. In fact, low vitamin D levels were associated with a 96 percent increased risk of low back pain in women. This association was not observed in men and was not linked to lower extremity pain in either sex.
A retrospective study published in Breast Cancer Research and Treatment (E-published ahead of print, March 8, 2011) examined vitamin D status in women with breast cancer. The study included 224 women with stage 0 to stage III breast cancer. Participants were divided into three groups: one received no vitamin D supplementation, one received 1,000 IU per day, and a third group received a high dose of 50,000 IU per day. Only the group receiving the high-dose vitamin D experienced a meaningful increase in serum 25-hydroxyvitamin D [25(OH)D] levels.
Research published in Tropical Medicine and International Health (October 2010; Volume 15, Issue 10, pp. 1148–1155) evaluated the effect of high-dose vitamin D supplementation in children recovering from pneumonia. The study involved 453 children between the ages of one and 36 months who were diagnosed with pneumonia. All children received antibiotic treatment and were randomly assigned to receive either a single 100,000 IU dose of vitamin D₃ or a placebo.
While there was no difference between the two groups in the time required for recovery from pneumonia, the group receiving vitamin D experienced a 22 percent reduction in the risk of recurrent pneumonia compared to the placebo group.
