Vitamin D supplements not VITAL to cancer prevention and heart health

In recent years, vitamin D supplements have gained popularity as a miracle solution for various conditions, such as heart disease, cancer, depression, fatigue, and weight gain. The number of people taking the hormone has surged, with approximately 26% of Americans aged 60 years and older taking vitamin D supplements.

While the hormone’s importance in calcium absorption and bone health has long been established, its benefits in other areas remain hazy and unsupported by clinical evidence. Nevertheless, the hormone’s popularity persists, even permeating health care practices. In 2016, physicians ordered more than 10 million lab tests for vitamin D deficiency for Medicare patients, costing taxpayers $365 million. Many of these lab tests did not have medical indications.

On January 3, 2019, findings of the widely anticipated VITAL (Vitamin D and Omega-3 Trial) study were published in the New England Journal of Medicine, providing the strongest and most exhaustive report to date on the hormone’s health outcomes outside of bone health. The study assessed the effects of high-dose vitamin D supplementation on the risk of invasive cancer or major cardiovascular (CV) events, such as myocardial infarction (MI), stroke, or death, in middle-aged patients who had no history of cancer or heart disease.

The large, multicenter, placebo-controlled study randomized 25,781 patients to a high dose of vitamin D of 2,000 I.U. per day (n = 12,927) or placebo (n = 12,944). Of these patients, 51% were women aged 55 years and older, and 49% were men aged 50 and older. The study was racially, ethnically, and geographically diverse, with black participants representing approximately 20% of the study population (n = 5,106).

Baseline vitamin D levels for 15,787 patients were evaluated in the beginning of the trial. Most patients were within the normal range, with an average serum total 25-hydroxyvitamin D level of 30.8 ± 10.0 ng/mL. However, 12.7% of those assessed had levels below 20 ng/mL, indicating vitamin D deficiency. The patients were followed for 5.3 years.

The study found that high-dose vitamin D supplementation did not reduce the risk of major CV events or invasive cancer types such as breast, prostate, and colorectal cancer. The occurrence of major CV events (hazard ratio 0.97 [95% CI 0.85 to 1.12]) and cancer (0.96 [0.88 to 1.06]) observed in the experimental and placebo groups were similar.

The effects of vitamin D did not vary according to baseline vitamin D levels or by race. However, a deeper look into the results shows a 23% reduction in cancer risk among black participants in the vitamin D group, suggesting possible protective effects. More research is needed to verify this finding.

For the full article, please visit www.pharmacytoday.org for the May 2019 issue of Pharmacy Today.