Association between dietary iron intake and bone mineral density: A cross-sectional study in Chinese population

Aim: The incidence of osteoporosis is rising continuously along with the ageing process in the Chinese population. Iron is an important trace element for bone growth, development and maintenance. However, the association of dietary iron with bone mineral density has not been widely investigated. The present study examined the cross-sectional association between dietary iron intake and phalangeal osteoporosis in the Chinese population. Methods: A total of 1870 subjects were included. Dietary intake was assessed using a semi-quantitative food frequency questionnaire. Bone mineral density scans were performed at the middle phalanges of the second, third and fourth fingers of the non-dominant hand. Then, a multivariable logistic analysis model was adopted to test the relationship between dietary iron intake and phalangeal osteoporosis after adjusting a number of potential confounding factors. Results: A modest inverse association between dietary iron intake and phalangeal osteoporosis was observed in the model adjusted by a set of factors, including sex, age, body mass index, smoking status, alcohol drinking status, exercise intensity, waist circumference, total energy intake, calcium intake, fibre intake, nutrient supplementation, history of hypertension and history of diabetes. This association existed both in the total subjects and in the female subgroup, especially in the postmenopausal female subgroup, but not in the male subgroup. Conclusions: The findings of the present study indicated that proper dietary iron intake may play a positive role in the prevention of osteoporosis in the female subgroup, especially in the postmenopausal female subgroup.