Nutrient intakes and bone mineral density of post-menopausal women residing in Northern Ireland

Abstract

Genetic factors explain about 80 % of bone strength (1) , however, bone mineral density (BMD) and bone metabolism are also affected by a number of environmental, hormonal and modifiable lifestyle factors, of which diet has been shown to play a prominent role (2) . Oestrogen depletion that occurs during the menopause has a negative effect on BMD, putting post-menopausal women at a greater risk of low BMD or osteoporosis (3) . The aim of this study was to compare intakes of macro- and micronutrients associated with bone health, between women with osteopenia and those with a normal BMD. Post-menopausal women (n 300) (45–75 years) were recruited between October 2008 and June 2009. Nutrient intakes were estimated for 291 women from 4-d food diaries. BMD was measured in the first to fourth lumbar vertebrae (L1–L4) and left proximal femur by dual-energy X-ray absorptiometry. Osteopenic women had significantly lower estimated dietary intakes of Ca, P and protein than those with normal BMD, with intakes of Ca below the UK reference nutrient intakes (RNI) (4) (Table 1). Spearman’s rank analysis revealed a positive correlation between protein intake (g/d) and femoral BMD (r = 0.02, P = 0.041), albeit no relationship between dietary Ca or P and BMD was found. Both groups had median intakes of Mg and vitamin D below the RNI.