Vitamin D Helps Heart During Weight Loss
A daily vitamin D supplement of 83 micrograms (mcg) may enhance heart health during weight loss efforts, according to a new study by German scientists. The study results appears in the current issue of the American Journal of Clinical Nutrition.
People who are overweight or obese often have several risk markers for cardiovascular disease, including high levels of triglycerides, tumour necrosis factor-alpha (TNF-alpha; a marker for inflammation), and parathyroid hormone. These and other markers join excessive body weight to increase the risk of experiencing a cardiovascular event. Investigators were curious as to what impact the addition of vitamin D may have on heart health and weight loss efforts by overweight or obese individuals.
Vitamin D deficiency is common in the United States. According to the Vitamin D Council, the optimal blood levels of vitamin D are 50 to 80 ng/mL (or 125-200 nmol/L), yet approximately 50 percent of Americans have much lower levels, with a higher percentage seen among the elderly. Deficient levels of vitamin D are associated with heart disease, hypertension, and stroke, and therefore people who are overweight or obese and who are on a weight loss program could help their heart by taking vitamin D.
The current study was a randomized, double-blind, placebo-controlled trial that included 200 healthy overweight individuals who had an average vitamin D level of 30 nmol/L (12 ng/mL). The participants were randomly assigned to receive either vitamin D or placebo for one year. All the subjects also participated in a weight loss program.
At the end of the study, participants who had taken vitamin D showed an increase in blood levels of vitamin D of 55 nmol/L (22 ng/mL) compared with only 11.8 nmol/L(4.7 ng/mL) in the placebo group. Patients in the vitamin D group also had reductions in risk markers for cardiovascular disease: a 26.5 percent reduction in parathyroid hormone levels compared with 18.7 percent in the placebo group; a 13.5 percent decrease in triglycerides compared with 3.0 percent; and a 10.2 percent decline in TNF-alpha compared with 3.2 percent. All of these benefits were independent of weight loss.
Results of this study indicate that including a vitamin D supplement of 83 mcg daily can improve several risk markers for cardiovascular disease in overweight, vitamin D deficient individuals while they participate in a weight loss program. There is even some evidence, although not yet verified, that adding vitamin D to a reduced calorie diet will improve weight loss efforts, according to study results presented at the Endocrine Society’s 91st Annual Meeting in June 2009.
Sibley S. Plasma Vitamin D: A Predictor of Subsequent Weight Loss Success. Endocrine Society’s 91st Annual Meeting
Vitamin D Council
Zittermann A et al. American Journal of Clinical Nutrition 2009 May; 89:1321-27