Vitamin D is important for many functions throughout the body especially immune system regulation and bone health. It appears that body mass may have a negative effect on your Vitamin D levels. According to PLOS Medicine, data analyzed from 21 studies involving 42,000 participants found that for each 10% rise in body mass index (BMI), there is a 4% drop of available vitamin D in the body. Since vitamin D is stored in fatty tissue, the authors suggest the larger storage capacity in obese people may prevent it from circulating in the bloodstream.
Healthy BMI is less than 25. It is important to know if you are at risk. You can easily test your body composition including BMI, cell membrane health, and water status with distribution with a Bioimpedance Analysis. Vitamin D levels can be measured via a simple blood test.