Some folks Ė especially advertisers Ė have picked up on the idea that extra calcium will help us lose weight. Iíve checked out some of the literature on the subject [not exhaustively, so donít take these comments to the bank just yet!], and the evidence is very unclear at the moment. Some studies suggest that dairy foods do help weight loss, and others donít.
But thereís a group out of Rutgers University in New Jersey thatís studying calcium metabolism in postmenopausal women who lose weight. We all know that this is a group that has a high rate of osteoporosis and osteopenia [decreased bone calcium]. While itís clear to these researchers that weight loss is associated with decreased bone mineral density and an increased risk of fracture in these women, they donít know why.
But their most recent study (Cifuentes M, Riedt CS, Brolin RE, Field MP, Sherrell RM, Shapses SA. Weight loss and calcium intake influence calcium absorption in overweight postmenopausal women. Am J Clin Nutr. 2005 Jan;81(1):199.) suggests that weight loss interferes with calcium absorption if youíre taking in the Ďnormalí amounts (1000 mg per day), and that hormones start taking calcium out of the bones even if your calcium intake is normal. But, among the dieting women who received higher levels of calcium (1800 mg per day), adequate amounts of calcium were absorbed.
Their conclusions, and Iím quoting the abstract here: ďWe suggest that weight loss is associated with elevated calcium requirements that, if not met, could activate the calcium-parathyroid hormone axis to absorb more calcium. Normal intakes of calcium during energy restriction result in inadequate total calcium absorption and could ultimately compromise calcium balance and bone mass.Ē
The translation: thereís something about weight loss that increases your need for calcium. If youíre not eating it, your body will start taking it out of your bones. You can prevent this by increasing your calcium intake.
But Iím also going to add that this makes it even more important that we do weight-bearing exercise, as this helps keep the calcium in the bone.
Calcium is essential, and Iím hoping that each and every one of you is getting enough. And this applies especially to those of us whoíve had WLS. We donít absorb most forms of calcium well, and combine this with the weight loss, and weíre at very high risk for problems. We donít want to end up being a normal weight, but crippled from broken bones!
This is an important issue. Talk to your doctor about it before you make any drastic changes, however. We need to be healthy. Thinness alone isnít enough.
And a PS. Brolin is a big name in WLS.