A Prospective Study to Identify Factors Affecting Adherence to Recommended Daily Calcium Intake in Women with Low Bone Mineral Density

OBJECTIVE: Factors that influence calcium intake among women with low bone mass have not been clearly identified. The objective of this study was to evaluate confidence, attitudes and beliefs regarding calcium intake and to identify determinants of adherence to calcium recommendations among women with low bone mineral density (BMD). METHODS: Participants were 104 women with low BMD attending an initial visit to an osteoporosis program. Prior to participation in a one-on-one standardized nutrition counseling session with a dietitian, daily calcium intake was assessed using four-day food records and use of calcium supplements was reported. Calcium related knowledge and beliefs were assessed by questionnaire. Barriers and facilitators to obtaining adequate calcium intake were also reported. Six months following baseline, food records and study questionnaire were repeated. Adherence was defined as meeting >=85% of recommended calcium intake. Logistic regression was used to examine baseline predictors of adherence to calcium recommendations at follow-up. RESULTS: Mean dietary calcium intake was 952 ± 384 mg/day at follow-up and 91.3% were using calcium supplements. Combining dietary and supplemental calcium, approximately 77% of women were adherent to calcium recommendations at follow-up. Uncertainty regarding calcium food sources and supplements, concerns related to weight gain and the fat content of some calcium-rich foods were the most frequently reported barriers to obtaining adequate calcium intake. The only significant independent predictor of calcium adherence at follow-up was use of a calcium supplement (adjusted OR = 5.970, p = 0.012). CONCLUSIONS: Due to the nutrient synergy of foods, dietary sources of calcium should continue to be promoted in nutritional counseling efforts as the optimal method of obtaining adequate calcium. Nutrition education should emphasize strategies to decrease side effects associated with calcium-rich foods and alleviate concerns regarding the cholesterol and fat content of some calcium-rich foods. In addition to strategies to increase consumption of dietary sources of calcium, supplementation should be considered as an acceptable method of increasing calcium intake among women with low BMD.