Back in March I wrote a blog which explored the concept that low levels of vitamin D may predispose the body the fatty accumulation. Part of the evidence for this comes from a couple of studies [1,2] cited in the blog which found this association in female teenagers and women aged 16-22 respectively. More recently, further research has emerged that appears to support this potential link.
In a study published in the journal Obesity last month, Spanish women aged 20-35 were divided into two groups according to their vitamin D levels [3]. Women with a vitamin D level of less than 90 nmol/l (36 ng/ml) were classified as ‘low D’ (LD), while women with a level of 90 nmol/l or more were classified as ‘high D’ (HD). Certain body measurements were then compared between the two groups.
The results of this study showed that body weight, body mass index and waist circumference were all higher in the LD group.
The average of each of these measures for LD and HD groups were:
Body weight: 76.2 and 68.6 kg
BMI: 28.6 and 26.0 kg/m2
Waist circumference: 86.2 and 79.4 cm
The first two of these measurements are, to my mind, pretty useless as they tell us nothing about the body’s composition or the distribution of any excess fat. The waist circumference is more useful, though, in that it is a proxy for excess weight congregating around the midriff (the form of excess weight most strongly associated with chronic diseases such as heart disease and type 2 diabetes).
The vitamin D intakes were similar between the two groups. The authors concluded that overweight/obese women are at higher risk of vitamin D deficiency, largely due to excess adiposity rather than inadequate intake. It is possible that being overweight increases the risk of vitamin D deficiency. For example, overweight and obese individuals may, for instance, get less sun exposure. Maybe they tend to go out less. Maybe they tend to wear more clothes when they do go out too.
However, the converse may be true too: vitamin D deficiency may cause individuals to put on weight.
A third possibility is that the association between vitamin D and body is just that ” an association ” and there is no ‘causality’ going on here one way or the other.
I am not aware of any science that demonstrates for certain that vitamin D deficiency can cause fatty accumulation in the body. However, what is becoming clear is that vitamin D has a role in many key body processes, also appears to have an influence in the development of and protection from a myriad of conditions. If it turns out that vitamin D does indeed influence body fatness, I won’t be surprised.
References:
1. Richard Kremer, et al. Vitamin D Status and Its Relationship to Body Fat Final Height, and Peak Bone Mass in Young Women. J Clin Endocrinol Metab 2009;94:67″73
2. Foss YJ. Vitamin D deficiency is the cause of common obesity. Medical Hypotheses 2009; 72(3):314-321
3. Rodríguez-Rodríguez E, et al. Vitamin D in Overweight/Obese Women and Its Relationship With Dietetic and Anthropometric Variables. Obesity 2009;17(4):778″782
