Obesity can lead to a lack of vitamin D circulating in the body, according to a study led by researchers at the University College London.


The study sought to find out whether a lack of vitamin D triggers a weight gain, or whether obesity leads to the deficiency.


They discovered that a 10 per cent rise in BMI was linked to a four per cent drop in vitamin D in the body.


The findings suggest that a higher BMI leads to lower levels of available vitamin D. The effect of a lack of vitamin D on BMI appears to be very small.


The association between obesity and vitamin D status found here was consistent between genders, being apparent both in men and in women, and in younger and older age groups.


Vitamin D, which is essential for healthy bones as well as other functions, is made in the skin after exposure to sunlight and can also be obtained through the diet and through supplements.


Vitamin D deficiency is a growing public health concern, and there is evidence that vitamin D metabolism, storage and action both influence and are influenced by body fat.


Overall, the study results suggest that although increases in vitamin D are not likely to help with weight regulation, increased risk of vitamin D deficiency could contribute to the adverse health effects associated with obesity.


Dr. Elina Hypponen

Dr. Elina Hypponen, lead author of the study, says: “Vitamin D deficiency is an active health concern around the world. Our study highlights the importance of monitoring and treating vitamin D deficiency in people who are overweight or obese, in order to alleviate adverse health effects caused by a lack of vitamin D.”




Vimaleswaran KS, Berry DJ, Lu C, Tikkanen E, Pilz S, et al. (2013) Causal Relationship between Obesity and Vitamin D Status: Bi-Directional Mendelian Randomization Analysis of Multiple Cohorts. PLoS Med 10(2): e1001383. doi:10.1371/journal.pmed.1001383