Dietary Iron Affects Bone Mineral Density

Dietary Iron Affects Bone Mineral Density

LITTLE ROCK, Ark.Dietary ironintake was associated with greater bone mineral density (BMD) in postmenopausalwomen, as noted by researchers at the University of Arkansas for MedicalSciences, Little Rock. Their study, which appeared in the November issue of the Journalof Nutrition (133, 11:3598-602, 2003) (www.nutrition.org), also indicateddietary iron may be more important in bone mineralization than has beenhistorically believed.

To investigate irons effects on BMD, researchers analyzeddata from the Bone, Estrogen and Strength Training (BEST) Study, which involved242 women 40 to 66 years old. BMD was measured at five sites, and nutrientintakes were calculated from three-day diet records. An analysis of the datashowed iron was associated with a greater BMD at all sites, even after adjustingfor protein and calcium intakes. In women with a mean calcium intake of 800 mg/dto 1,200 mg/d, increasing levels of iron intake (greater than 20 mg/d) seemed tolead to greater BMD at several bone sites. However, in women with higher (greater than 1,200 mg/d) andlower (less than 800 mg/d) calcium intakes, elevated iron was not associatedwith BMD. Researchers suggested additional research is needed to clarify thesynergistic effect calcium and iron have on BMD.