A high level of visceral fat, or abdominal fat, is associated with lower vitamin D levels in obese individuals, according to a study by VU Medical Center and Leiden University Medical Center in the Netherlands. This links vitamin D deficiency to overweight.
Overweight and vitamin D deficiency
In the study, physician-researcher Rachida Rafiq and her colleagues investigated how the amount of body fat and abdominal fat, measured in participants in the Netherlands Epidemiology of Obesity study, was related to their vitamin D levels. After adjusting for several possible confounding factors, including chronic disease, alcohol consumption and levels of physical activity, they discovered that the greater the amount of abdominal fat, the lower the levels of detected vitamin D. In women, both the amount of body fat and abdominal fat were associated with lower vitamin D levels; in men, this was particularly the case for abdominal fat and liver fat.
Rachida Rafiq:
"Although we did not measure vitamin D deficiency in our study, the strong relationship between increasing amounts of abdominal fat and lower vitamin D levels suggests that people with a larger waistline are at greater risk of developing a deficiency and should consider having their vitamin D levels checked to potentially prevent harmful effects on health."
Obesity
Obesity is a global epidemic and causes approximately 2.8 million deaths worldwide each year. Vitamin D deficiency is usually associated with impaired bone health, but in recent years it has also been linked to higher risks of acute respiratory infections, autoimmune diseases and cardiovascular disease. Although more research is needed, a link has now also been demonstrated between low vitamin D levels and obesity. For this reason, vitamin D deficiency is associated with overweight.
Rachida Rafiq:
"Due to the observational nature of this study, we cannot draw any conclusions about the cause of the association between obesity and vitamin D levels. However, this strong association may indicate a possible role for vitamin D in the storage and function of abdominal fat."
Further research needed
The researchers now plan to investigate what underlies this strong association between vitamin D levels and obesity: whether a lack of vitamin D makes individuals susceptible to storing fat, or whether increased fat levels are the cause of declining vitamin D levels.