Meta-study: lower vitamin D levels, more excess weight
If there is sufficient vitamin D in your blood, your chance of being overweight is smaller than if the concentration of vitamin D in your blood is sub-optimal. And the higher your BMI, the stronger the connection. This is interesting, because in many countries nearly half of the population has less vitamin D in their system than scientists consider optimal.
Danish scientists, affiliated with the University of Aarhus, found 55 previously published studies in which researchers had measured both vitamin D levels and BMI in large groups of people. The Danes aggregated the results of these studies and analyzed them again.
From 45 studies, the researchers selected data about people without diabetes and combined them. Then the researchers split the data into three groups: the first group of data related to people with a BMI of 18-25, the second to people with a BMI of 25-30 and third to people with a BMI of over 30.
In all groups the BMI was lower as more vitamin D was in the subjects' blood, but in the group with the highest BMI the link was strongest.
Click on the figures below for a larger version.
The researchers did the same with the data from people with diabetes, and came to the same conclusion. In this group, the link between vitamin D and BMI was even stronger than in the group without diabetes.
Epidemiological research such as this shows associations, and not every association is a causal relationship. But because other studies suggest that vitamin D affects the way in which muscles deal with fat and energy, it is quite possible that a low vitamin D level is indeed a factor in obesity.
How you can optimize your vitamin D level with supplements can be read here and here.
Nutrients. 2018 Aug 28;10(9).
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