Calcium, Vitamin D Aid Weight Loss

BEER-SHEVA, IsraelCalcium and vitamin D increased weight loss for those following a diet in a recent two-year study (Am J Clin Nutr. 2010 Sep 1. doi:10.3945/ajcn.2010.29355). Researchers from the Ben-Gurion University of the Negev, Beer-Sheva, Israel, found both higher dairy calcium intake and increased blood concentrations of vitamin D were related to greater diet-induced weight loss.

The scientists, lead by Danit R Shahar, analyzed data from participants in the two-year Dietary Intervention Randomized Controlled Trial (DIRECT). Subjects (n = 322) had a mean body mass index (BMI) of 31 and a mean age 52 years. The researchers measured changes in serum vitamin D of 126 of the subjects as well.

The researchers found baseline serum 25-hydroxyvitamin D [25(OH)D] concentrations decreased significantly among those who had higher BMIs. Those with the smaller BMIs had vitamin D levels of 25.6 ± 8.0 ng/mL, and those with the highest BMIs had 22.9 ± 6.8 ng/mL, (P for trend = 0.02).

In repeated-measures models adjusted for age, sex, baseline BMI, total fat intake and diet, higher six-month levels of dairy calcium intake and serum 25(OH)D were associated with increased weight loss across the two-year intervention.

They found individuals who consumed a median of 156.5 mg/d of dairy calcium experienced an average weight loss of 3.3 kg, those who consumed 358 mg/d lost 21.2 kg, and those who consumed 582.9 mg/d lost 5.3 kg (P = 0.043). The Institutes of Medicine (IOM) recommend 1,000 to 1,500 mg/d of total calcium intake.

Those who had serum vitamin D levels of 14.5 ng/mL lost 3.3 kg, those with 21.2 ng/ml lost 3.5 kg, and those with 30.2 ng/ml lost 5.3 kg (P = 0.013). A vitamin D serum concentration above 15 ng/ml is generally considered adequate for those in good health, however some experts believe levels above 30 ng/ml are desirable for achieving optimum health.

 Further, in a multivariate logistic regression adjusted simultaneously for age, sex, baseline BMI, total fat intake, diet group, vitamin D concentration and dairy calcium, an increase of one standard deviation in dairy calcium intake increased the likelihood of weight loss of by more than 4.5 kg in the preceding six months  [P = 0.046]. A similar increase was seen for serum 25(OH)D at the 6-month point (P = 0.009).

However, baseline concentrations of vitamin D and dairy calcium intake were not associated with subsequent weight loss.

This study was supported by the Israeli Dairy Council, the Israeli Ministry of Health, the German Research Foundation grant and the Dr. Robert C. and Veronica Atkins Research Foundation.