Vitamin D Supplementation Does Not Affect Obesity-Related CV Risk Factors

According to the recent results of a prospective, double-blind, randomized trial, supplementation with 400 IU or 2000 IU of vitamin D3 did not alter cardiometabolic disease (CMD) risk factors in obese adolescents, although it did produce a modest increase in serum levels of 25 hydroxy-vitamin D [25(OH)D].

Asma Javed, MD, of the Mayo Clinic in Rochester, and colleagues revealed their findings at ENDO 2013: The Endocrine Society’s 95^th Annual Meeting and Expo in San Francisco on June 17, 2013.

According to the researchers, vitamin D deficiency has been found in up to 80% of obese children. An association has been shown observationally between vitamin D and low HDL, increased glucose, and insulin resistance. There is currently no evidence regarding response in lipid levels and cardiometabolic risk factors to vitamin D supplementation; the authors sought to evaluate these effects with two different doses of vitamin D supplementation in obese adolescents.

For this study, 12-18 year old obese adolescents (BMI > 95^th percentile) were randomized to receive either 2000 IU vitamin D3 daily (n = 23) or 400 IU vitamin D3 daily for 12 weeks. Laboratory values were obtained at baseline and at 12 weeks. These included serum 25(OH)D, fasting plasma glucose, insulin, total cholesterol, high-density cholesterol, triglycerides, high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), total (T) adiponectin, high molecular weight (HMW) adiponectin, and retinol-binding protein 4 (RBP4).

Results showed a median serum 25(OH)D level increase of 5 ng/ml (p = 0.039) in subjects who received 2000 IU vitamin D3 per day. However, the serum 25(OH)D level change was negligible in subjects who received only 400 IU daily (p = 0.4). In regards to the measured CMD risk markers, there were no significant changes found in either treatment group (p>0.05 for all).

The authors concluded that the lack of response in the CMD risk markers could indicate a need for a higher vitamin D3 supplementation dose for obese adolescents or longer duration of supplementation. They also propose that because there was only a modest increase in serum 25(OH)D, the effect on CMD risk markers was insufficient at this dose. Alternatively, vitamin D status may not be the only influence on obesity-related risk factors in this population. Further research is warranted.

The authors have nothing to disclose.