Obesity can cause Vitamin D deficiency, according to a study published in a recent issue of PLoS Medicine.

The study, led by researchers from the D-CarDia collaboration, is the first to associate a high BMI with low Vitamin D levels. The implications of the finding are significant as it suggests that as obesity increases in the world so does Vitamin D deficiency, which can pose a serious range of health issues.

Over 42,000 people from 21 countries participated in the study. The researchers tried to identify any genetic variations that could be involved with BMI and Vitamin D to ensure that there were no other factors that could influence the results.

They found that the association between high BMI and low Vitamin D was consistent among all different demographic groups. For each 10% increase in BMI there was a 4.2% drop in Vitamin D. Vitamin D scores appeared to have no link to BMI, indicating that the association between the two is more likely a Vitamin D lowering effect caused by a high BMI.

The authors said:

“We demonstrated that the association between BMI and lower (Vitamin D) concentrations in Caucasian populations from North America and Europe can be seen across different age groups and in both men and women. We also show that higher BMI leads to lower Vitamin D status, providing evidence for the role of obesity as a causal risk factor for the development of Vitamin D deficiency.”

The finding reveals the importance of monitoring and measuring Vitamin D levels among those who are obese. Vitamin D is essential for bone health as well as preventing cancer, diabetes and high blood pressure.

A recent study carried out by researchers from the University of Copenhagen found that low levels of Vitamin D can substantially increase one’s risk of heart attack and early death.

The authors concluded:

“Together with the suggested increases in Vitamin D requirements in obese individuals, our study highlights the importance of monitoring and treating Vitamin D deficiency as a means of alleviating the adverse influences of excess adiposity on health.Our findings suggest that population level interventions to reduce obesity would be expected to lead to a reduction in the prevalence of Vitamin D deficiency.”

It seems that obesity may place a person’s body into a vicious cycle of low Vitamin D and type II diabetes.

Researchers found that when somebody is both obese and has low Vitamin D levels, their risk of insulin resistance is much greater than if they have either factor alone. In other words, Vitamin D deficiency plus obesity, combined, increases your risk of developing insulin resistance much more than just obesity or just low Vitamin D.

Shaum Kabadi, from Dextrel University, said “Vitamin D insufficiency and obesity are individual risk factors for insulin resistance and diabetes. Our results suggest that the combination of these two factors increases the odds of insulin resistance to an even greater degree than would have been expected based on their individual contributions.”

Kabadi and team found that people with healthy levels of Vitamin D who were obese were nearly 20 times more likely to suffer from insulin resistance, compared to the rest of the population. However, obese people with low serum Vitamin D were 32 times more likely to have insulin resistance.

Written by Joseph Nordqvist