A new study from Spain reports that vitamin D deficiency may increase the chances of becoming obese years later.
The observational study measured blood vitamin D concentrations and documented cases of obesity among 1,226 participants who were not obese (BMI below 30 kg/m2) at the beginning of the study, with three evalu-ations over the course of 12 years (1). The results showed that participants who had low vitamin D levels six to eight years after the beginning of the study were much more likely to become obese four to six years later compared to those with higher vitamin D levels. Specifically, those with levels lower than 17 ng/ml (42.5 nmol/l) had a 2.35-times higher risk of becoming obese than those with levels over 17 ng/ml.
The researchers commented that obesity is a known risk factor for vitamin D deficiency because the more someone weighs, the more vitamin D he/she needs. However it is difficult to find out whether vitamin D makes people more susceptible to becoming obese, or if obesity makes people deficient, or a combination of both. The advantage of the present study is that vitamin D levels were evaluated in non-obese people at the beginning of the study, after which the researchers assessed whether these people with various vitamin D levels gained weight, lost weight or stayed the same. Based on the study results, the researchers concluded that lower vitamin D values in obese people may not have been secondary to obesity, but may in fact pre-cede obesity. Thus, low vitamin D levels seem to make people more susceptible to becoming obese.