Dietary mineral insufficiency and osteoporosis risk across skeletal sites in older Iranian adults: IMOS-2021.

INTRODUCTION: The aim of this study was to examine Iranian adults aged 50 and above to determine the association between the prevalence of regional osteoporosis and their dietary intake of phosphorus, magnesium, potassium, and zinc. MATERIALS AND METHODS: We conducted a cross-sectional analysis of 1353 participants (406 with osteoporosis, 947 healthy) from the Iranian Multicenter Osteoporosis Study (IMOS-2021). A validated 168-item food frequency questionnaire was utilized to evaluate dietary intake. The lumbar spine, whole hip, and femoral neck were assessed for bone mineral density (BMD) with dual-energy x-ray absorptiometry. Multivariable logistic regression models were used to estimate odds ratios (ORs) for osteoporosis, adjusting for potential confounders. RESULTS: Participants with osteoporosis were significantly older (63.76 vs. 59.61 years, P < 0.001), more likely to be women (67.2% vs. 50.4%, P < 0.001), and had lower intakes of all measured minerals (all P < 0.001). Correlation analyses revealed significant positive associations between all minerals and BMD at all skeletal sites (all P ≤ 0.01). In univariable models, insufficient phosphorus intake was associated with spine osteoporosis (OR = 1.56, P = 0.006) and total osteoporosis (OR = 1.49, P = 0.008), while insufficient potassium intake was linked to total osteoporosis (OR = 1.79, P = 0.031). After adjustment, only insufficient phosphorus intake remained significant for spine osteoporosis (OR = 1.71, P = 0.008). CONCLUSION: Our findings suggest that dietary phosphorus may be independently associated with osteoporosis risk in this population; however, prospective studies incorporating objective dietary assessment, broader lifestyle factors, and fracture-related outcomes are needed to confirm causality and address residual confounding.