Objective: To investigate the relative contribution of dietary calcium intake on bone mineral density (BMD) and biochemical bone turnover markers in rural Thai women.
Material and method: A cross-sectional investigation was designed in 255 rural Thai women. Usual dietary calcium intake was determined by 3-day food records and quantitative food-frequency questionnaire. BMD was measured by DXA. The three markers for bone turnover event: serum total alkaline phosphatase, serum N-mid osteocalcin and type I collagen C-telopeptide, including serum calcium and were determined in 125 women in the present study.
Results: An average daily calcium intake in the present study was 265 mg/day. Two hundred and thirty three out of 255 women (87%) consumed dietary calcium less than half of the recommended value and only 3% of women (n = 7) had calcium intake > 800 mg/day. After controlling certain parameters: age and body mass index, women who consumed higher amount of dietary calcium had significantly higher BMD at all sites. Moreover highly increased bone turnover markers were observed in those with lowest quartile calcium intake. Women with osteopenia and osteoporosis were older, lower BMI, consumed less calcium and had significantly higher values of all biochemical bone turnover markers than those who had normal BMD.
Conclusion: The present study showed that a habitual diet of the rural Thai population might not provide enough calcium as needed for bone retention and for prevention of bone loss in the following years. Modification of eating pattern by promotion of increased consumption of locally available calcium rich food may be beneficial for prevention of osteoporosis among this population.