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!
In The News
March 18th, 2009 at 7:46 am
Hi Arya:
Nice post. You should consider joining the researchblogging.org network - it is a nice way to find blogging posts about clinical research, and it exposes your writing to an even larger audience.
March 18th, 2009 at 11:11 am
Thank you for your comment on this study! I really appreciate it because in the news paper they claim that calcium will lead to weight loss and I am preoccupied by the idea that a lot of people will go buy calcium (instead of drinking milk, eating yogourt or cheese) to loose weight and believe that this is the answer… Il like the precision you made about who can beneficiate of calcium.