Race‐Ethnic Patterns in Iron Intake and Status in US Women: Findings from NHANES 2003‐06

Abstract

Race‐ethnic differences in iron status of US women have been reported previously. We examined the association of race‐ethnicity with iron intake from diet and supplements and with iron status in a nationally representative sample of non‐pregnant, non‐lactating 20‐49 y old women who participated in NHANES 2003‐06 (n~1850). Iron intake from supplements (SupplFe) over the last 30 d was recorded at an in‐home interview. Dietary iron (DietFe) intake was estimated via a 24‐h recall obtained using USDA's multiple pass method. Blood was analyzed for serum ferritin (FER), transferrin saturation (TS), and soluble transferrin receptor (sTfR). Body iron (mg/kg) was estimated as the molar ratio of sTfR to FER. Significant correlations were noted between total iron intake (diet and supplements) and some iron status indicators: TS (rho=0.16, p<0.0001) and FER (rho=0.08, p<0.02); DietFe intake was not associated with iron status. DietFe intake was related to race‐ethnicity overall (p=0.01) and in iron‐supplement users (p=0.02), with non‐Hispanic blacks (NHB) having lower DietFe intake compared to non‐Hispanic whites (NHW) and Mexican Americans. Interestingly, SupplFe intake was not related to race‐ethnicity. Iron status indicators (TS, sTfR, and body iron) were associated with race‐ethnicity overall and in iron‐supplement users and nonusers (except for body iron) (p<0.01), with NHB having lower iron status versus NHW. In conclusion, race‐ethnicity was related to iron intake and status and patterns varied with iron supplement use. NHB race‐ethnicity tended to have lower iron intake and status, which deserves further attention.