By James Keough
Researchers and mothers alike have long known that vitamin D builds strong bones, but who would have thought the sunshine vitamin played a critical role in heart health as well?
A recent German study found that high-dose vitamin D supplements decreased the levels of an inflammation-causing cytokine and boosted concentrations of interleukin 10, an anti-inflammatory cytokine. (Various types of cells secrete cytokines as part of the body’s immune system. The cytokines bond to specific cell-surface receptors and tell the cell how to react to a specific threat.)
The vitamin D and heart health connection comes from the role inflammation seems to play in many of the underlying causes of congestive heart failure (CHF)—hypertension, myopathy, diabetes, and coronary artery disease. Vitamin D also boosts muscle function, another critical factor in CHF, which affects about 5 million Americans.
The study built on earlier in vitro work, which suggested that vitamin D suppressed pro-inflammatory cytokines and increased anti-inflammatory ones. To test that finding in humans, researchers gave 123 heart patients either 50 mg (2,000 IUs) of vitamin D3 plus 500 mg of calcium a day or a placebo plus calcium.
After nine months, blood serum levels of vitamin D in the supplemented group had increased more than seven times that of the control group; a major pro-inflammatory cytokine remained constant in the supplemented group but increased in the controls. Interleukin 10 was significantly higher in those who received vitamin D. The study also looked at left ventricular function and at survival rates after 15 months and found no change in either.
Despite its lack of a direct therapeutic effect for this group of CHF patients, supplementing with vitamin D seems even more important in the struggle against chronic inflammation than anyone ever dreamed. Just don’t try to boost your daily intake anywhere near the level in this study without first consulting your doctor.
Healthy levels of vitamin D help your body in myriad ways, but too much can have the opposite effect. The Food and Nutrition Board of the Institute of Medicine has set the tolerable upper intake level (UL) for vitamin D at 25 mg (1,000 IU) for infants up to 12 months of age and 50 mg (2,000 IU) for children, adults, and pregnant or lactating women. So by all means supplement, but also factor in how much sun you get each day and how much vitamin D you might receive from food.