Calcium+Vit D Promotes Fat Loss in Severely Calcium-Deficient Women

I have previously blogged about the high prevalence of Vit D deficiency in bariatric patients. A natural consequence of Vit D deficiency and/or low calcium intake is secondary hyperparathyroidism, necessary to maintain normal calcium levels in the blood.

Apart from the importance of adequate calcium and Vit D intake for bone health, Increased calcium intake has also been suggested to help with weight loss.  However, interventions studies on this have not been conclusive.

This may be because, calcium (+Vit D) supplementation perhaps only aids weight loss in people with low calcium (and/or Vit D?) intake. This at least is suggested by a new study by Genevieve Major and colleagues from Laval University, Ste-Foy, Quebec, Canada, published in this month’s issue of the British Journal of Nutrition.

In this randomized, double-blind, placebo-controlled study, 63 overweight or obese women, who reported consuming less than 800 mg of calcium per day, underwent a 15-week weight-reducing programme either with calcium plus vitamin D (calcium+D) supplementation (600 mg elemental calcium and 5 microg vitamin D, consumed twice a day) or with a placebo.

While there was no overall effect of calcium+D on fat loss in the whole group, when analyses were limited to the rather small number (n=13) of very low-calcium consumers (initial calcium intake < or =600 mg/d), a significant decrease in body weight and fat mass (P < 0.01) and in spontaneous dietary lipid intake (P < 0.05) was observed in the calcium+D (n=7) but not in the placebo (n=6) group.

This study, thus suggests that there may be a beneficial effect of calcium+D supplementation on fat loss in women who have very low calcium/Vit D intakes and that this effect may be due to changes in their fat intake. In contrast, there does not appear to be any benefit of calcium+D in women who report consuming more than 600 mg calcium per day.

The mechanism underlying these observations is not clear, but may be related to an effect of calcium (or calcium-regulating hormones) on macronutrient selection.

Thus, while calcium+D supplementation does not appear to be a panacea for weight loss, it may indeed be an essential factor in the treatment of obesity in women (and men?) with los calcium intake (and/or Vit D deficiency?).

However, given the post-hoc nature of this analysis and the rather small number of subjects, one may need to take these observations with a grain of salt and await the results of more conclusive studies on this important issue.

AMS
Edmonton, Alberta

Hat tip to Émilie Dansereau-Trahan for suggesting this article!