A Study of Nutrient Intake and Serum Levels of Osteocalcin, Ca, P, and Mg and Their Correlation to Bone Mineral Density in Korean Postmenopausal Women Residing in Rural Areas

Sung, Chung Ja; Choi, Yun Hee; Kim, Mi Hyun; Choi, Sun Hae; Cho, Kyung Ok

Abstract

Postmenopausal women lose more bone mass than men as a result of estrogen deprivation. The resultant low bone mineral density (BMD) is a major risk factor in the development of osteoporosis. Calcium, phosphorus and magnesium are main components of bone. The purpose of this study is to investigate nutrient intake and serum osteocalcin, Ca, P and Mg and their correlation to bone mineral density in Korean postmenopausal women residing in rural areas. We conducted 24 hour dietary recalls, anthropometric measurements and blood analysis on 60 postmenopausal women. The BMD of the lumbar spine (L2-->L4) and the femoral neck were measured by dual energy X-ray absorptiometry (DEXA). Subjects were assigned to one of three groups:normal (T-score> -1, n=20), osteopenia (-2.5> T-score< or = -1, n=23), and osteoporosis ( T-score< or = -2.5, n=17). The mean age, height, weight and BMI were 62.37 yr, 154.36 cm, 55.28 kg and 23.18 kg/m2 respectively. The mean daily energy and protein intakes were 76.35% and 87.41% of RDA for Koreans. The mean intakes of calcium, phosphorus, and magnesium were 463.62 mg (66.23% of RDA), 955.32 mg (136.47% of RDA), 345.87 mg respectively. The mean serum levels of calcium, phosphorus and magnesium were 8.76 mg/dl, 3.80 mg/dl, and 2.10 mg/dl, respectively, and there were no significant differences among the three groups. However, the BMD of the femoral neck showed a significantly negative correlation with serum magnesium (p<0.05). To summarize the results, most nutrient intakes (especially calcium) in postmenopausal women did not reach the RDA values for Koreans. Also, increase of serum magnesium levels may be related to bone loss.