By Alan Mozes
The finding highlights yet another damaging health effect of obesity. Low vitamin D levels have been linked to poor bone health, as well as increased risk for respiratory infection, autoimmune disorders and heart disease.
"The strong relationship between increasing amounts of abdominal fats and lower levels of vitamin D suggests that individuals with larger waistlines are at a greater risk of developing deficiency, and should consider having their vitamin D levels checked," said study author Rachida Rafiq.
Rafiq is a doctoral student at VU University Medical Center and Leiden University Medical Center in the Netherlands.
Her team is slated to present the findings at a meeting this week of the European Society of Endocrinology, in Barcelona, Spain.
The findings stem from an analysis of data collected by the Netherlands Epidemiology of Obesity study. It linked higher levels of abdominal fat to an added likelihood of low vitamin D levels among both men and women who are obese.
Among obese men, higher levels of total overall fat were also linked to lower vitamin D levels. The same link was not found for obese women.
Among obese women, however, higher amounts of liver fat were linked to low vitamin D, a finding not seen among obese men.
It remains unclear, however, whether low vitamin D causes people to store abdominal fat or whether excess belly fat somehow triggers vitamin D levels to drop, Rafiq said. That will be a focus for future study, researchers said.
"Due to the observational nature of this study, we cannot draw a conclusion on the direction or cause of the association between obesity and vitamin D levels," Rafiq said in meeting news release. "However, this strong association may point to a possible role for vitamin D in abdominal fat storage and function."
Research presented at meetings is considered preliminary until published in a peer-reviewed journal.