Vitamin D research is progressing at a rapid pace! When we were recently asked a question about Vitamin D, we performed a quick search to see if there were any new research, and lo and behold, we came across this little gem, which was only 2 days old! Unfortunately, we have not been able to obtain the complete article as of yet, but the abstract appears to be interesting.
The first point to emphasise is that this is a cross-sectional study, and to echo earlier sermons… This type of research does not demonstrate cause and effect. It is non-mechanistic and only displays associations and trends. Low Vitamin D levels were linked to increased weight growth, body fatness (skinfold thickness), and waist circumference in the study. In this case, one initial hypothesis is that children with the lowest serum vitamin D levels may be the ones who spend the least time outside and hence get the least exercise. While regular exercise does not normally have a significant impact on body weight, it may be suggestive of a healthier lifestyle in general.
Just an idea. It’s also a case of chicken and egg… Was the adiposity caused by a lack of Vitamin D, or was it caused by a hereditary predisposition to gain weight? It’s worth noting that this study was conducted in Bogota, Colombia, which has significantly more sun than the UK, and yet the youngsters there were deficient in the’sunshine vitamin’… thought-provoking…
DESIGN: Vitamin D status was assessed as inadequate [25(OH)D concentrations 50 and 75 nmol/L], insufficient [25(OH)D concentrations 50 and 75 nmol/L], or sufficient [25(OH)D concentrations 75 nmol/L] in 479 kids aged 5-12 years.
RESULTS: Children who were vitamin D deficient had an adjusted 0.1/y larger change in BMI than children who were vitamin D sufficient. Similarly, vitamin D-deficient children exhibited a 0.03/y higher change in subscapular-to-triceps skinfold thickness ratio and a 0.8 cm/y higher change in waist circumference than vitamin D-sufficient children.
CONCLUSION: Vitamin D serostatus was found to be inversely related to the development of obesity in school-aged children.
In Spanish kids, similar relationships between abdominal fat, BMI, and vitamin D status have been discovered.
Update: Following the publication of this blog, another study in this area was released titled: Preliminary findings on the influence of vitamin D level on body fat loss in young overweight/obese women following two forms of hypo-caloric diet.
In this study, women were randomly assigned to one of two diets: one that raised their consumption of vegetables, and the other that increased their relative consumption of cereals (particularly breakfast cereals). Women in each group were classified as having low Vitamin D (LD; 50 nmol/l) or high Vitamin D (HD; >or=50 nmol/l) (see sidebar for what these levels equate to). Both of these diets resulted in lower calorie consumption, body weight, and BMI in LD and HD.
However, the HD women lost more body fat than the LD women (1.7kg compared to 0.5kg). When the dietary categories were examined independently, this impact was only detected in the subjects who consumed more cereal, who most likely got a higher amount of Vitamin D due to fortification. As a result, the study concluded: “The current findings imply that women with a higher vitamin D status respond more positively to hypo-caloric diets and shed more body fat; this was notably evident among participants who had a higher vitamin D supply during the experimental period.”