High blood concentrations of parathyroid hormone and low concentrations of the vitamin D metabolites 25-hydroxyvitamin D [25(OH)D] and calcitriol are considered new cardiovascular disease risk markers. However, there is also evidence that calcitriol increases lipogenesis and decreases lipolysis.
Objective
We investigated the effect of vitamin D on weight loss and traditional and nontraditional cardiovascular disease risk markers in overweight subjects.
Design:
Healthy overweight subjects (n = 200) with mean 25(OH)D concentrations of 30 nmol/L (12 ng/mL) received vitamin D (83 μg/d) or placebo in a double-blind manner for 12 mo while participating in a weight-reduction program.
Results:
Weight loss was not affected significantly by vitamin D supplementation (−5.7 ± 5.8 kg) or placebo (−6.4 ± 5.6 kg). However, mean 25(OH)D and calcitriol concentrations increased by 55.5 nmol/L and 40.0 pmol/L, respectively, in the vitamin D group but by only 11.8 nmol/L and 9.3 pmol/L, respectively, in the placebo group (P < 0.001), whereas a more pronounced decrease occurred in the vitamin D group than in the placebo group in blood concentrations of parathyroid hormone (−26.5% compared with −18.7%; P = 0.014), triglycerides (−13.5% compared with +3.0%; P < 0.001), and the inflammation marker tumor necrosis factor-α (−10.2% compared with −3.2%; P = 0.049). The beneficial biochemical effects were independent of the loss in body weight, fat mass, and sex. However, compared with placebo, vitamin D supplementation also increased LDL-cholesterol concentrations (+5.4% compared with −2.5%; P < 0.001).
Conclusions:
The results indicate that a vitamin D supplement of 83 μg/d does not adversely affect weight loss and is able to significantly improve several cardiovascular disease risk markers in overweight subjects with inadequate vitamin D status participating in a weight-reduction program. This trial was registered at clinicaltrials.gov as NCT00493012.
Supported by different German health insurance companies and the ‘Institut für Angewandte Telemedizin,’ Herzzentrum NRW, Ruhr Universität Bochum, Bad Oeynhausen, Germany. Vitamin D was provided by Merck KgaA, Darmstadt, Germany.