Gonzalez A, White E, Kristal A, Littman A. Calcium intake and 10-year weight change in middle-aged adults. J Am Diet Assoc 2006l; 106:1066-1073.
A study conducted at Fred Hutchinson Cancer research center in Seattle, Washington evaluated the effect of dietary and supplemental calcium on 10-year weight change in 5250 men and 5341 women from the Vitamins and Lifestyle (VITAL) study. The participants ranged in age from 53 to 57, and completed questionnaires about their supplement use for the 10 years prior to the study and their dietary calcium intake for the immediately preceding year. The subjects’ height, current and previous weights, exercise, smoking history, and demographic characteristics were recorded.
Most individuals in the study were Caucasian and well educated, and all except 8% were nonsmokers. Women in the study had an average dietary calcium intake of 811 mg/day in the year preceding the study, and the average dietary calcium and supplemented calcium totaled 1094 mg/day.
Women who took 500 mg or more of supplemental daily calcium either during the study or during the previous 10 years had a significantly smaller weight gain over those 10 years than women who did not take supplemental calcium. The difference was about 4 lb. Dietary calcium alone was not associated with a smaller weight gain, and calcium intake in men had no effect on weight gain.
Commentary
Previous research has elucidated an inverse relationship between calcium intake and weight gain. This study seems to support that observation. However, the study is limited by the reliability of self-reported body weights and supplement dosing over the 10 year pre-study period. We cannot feel confident that this study provides adequate evidence for recommending either calcium supplements or dairy products to middle aged women as means for achieving weight stability. On the other hand, there are compelling reasons for women to have an adequate calcium and vitamin D intake as they age. Perhaps this will also give them the small benefit of less weight gain during aging.
