Dietary iron intake and its impact on osteopenia/osteoporosis

Osteoporosis is a prevalent condition characterized by low bone density and increased risk of fractures, resulting in a significant healthcare burden. Previous research has suggested that serum ferritin levels may be related to the risk of developing osteoporosis. The aim of this study was to investigate the relationship between dietary iron intake and the development of osteoporosis.

Using data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2018, a total of 11,690 adults aged over 20 were evaluated. Bone mineral density (BMD) measurements of the femoral neck and lumbar spine were used to assess osteoporosis and osteopenia. Dietary iron intake was determined using food intake interviews and the Food and Nutrient Database for Dietary Studies. Logistic regression models were applied to investigate the association between dietary iron consumption and osteopenia and osteoporosis.

After adjusting for sociodemographic factors, compared with those who had the first quartile (Q1) of dietary iron intake, the odds ratio (OR) for osteopenia across the quartiles of dietary iron intake levels was 0.88 (95%CI: 0.79-0.98), 0.80 (95%CI: 0.72-0.89), and 0.74 (95%CI: 0.67-0.83) for Q2, Q3, and Q4, respectively. And the OR for osteoporosis across the quartiles of dietary iron intake levels was 1.00, 0.77 (95%CI: 0.50-1.19), 0.54 (95%CI: 0.34-0.89), and 0.83 (95%CI: 0.54-1.29) for Q1, Q2, Q3, and Q4, respectively. Notably, the observed association was significant among females but not males.

The risk of osteopenia/osteoporosis in females decreases with a moderate increase in dietary iron consumption. For females to preserve bone health, moderately increasing their dietary iron intake without overindulging should be seen as a key approach. Our study provides useful insights for developing dietary strategies to prevent and manage osteoporosis in vulnerable populations.