Dietary intervention effective in treating iron deficiency - Iron Deficiency - Brief Article

Nutrition Research Newsletter, Nov, 2001

Women of childbearing age are the population at the greatest risk of becoming iron deficient due to the effects of menstruation and pregnancy. At this time, there has been few if any studies performed regarding the role of dietary intervention in the treatment of iron deficiency. The alternative to dietary intervention is iron supplementation, which often has a high rate of noncompliance secondary to marked side effects. It can be hypothesized that dietary intervention in women of child-bearing age may have an advantage over supplementation in relation to compliance, long-term acceptability, cost-effectiveness, risk of iron overload, and beneficial effect on the iron intake of the entire family.

The aim of a recent, Australian study was to compare the effects of standard iron supplementation and a high-iron diet on iron deficiency in women of childbearing age. Forty-eight women with iron deficiency, as defined by serum ferritin concentration of <15 micrograms/L or a serum ferritin concentration of 15-20 micrograms/L plus a serum iron concentration of< 10 micrograms/L and a total-iron-binding capacity >68 micrograms/L, completed the study. Twenty-two iron-replete control subjects, matched to the iron-deficient women by age and parity, also completed the study. The subjects with iron deficiency were randomly assigned within their age groups and parity categories to either the diet or supplement group. The supplement intervention asked subjects to take 350-mg slow-release ferrous sulfate each day on an empty stomach for a duration of 12 weeks. Compliance was measured using a diary system. This group received no dietary advice. The subjects in the diet group were asked to follow a high-iron diet, intended to provide 2.25 mg/day of absorbable iron, for a 12-week period. Subjects in this group were given meat vouchers sufficient to purchase 120 gm high-quality beef or lamb per day for 12 weeks and received nutritional counseling from a dietitian regarding the high iron diet. They were also encouraged to consume iron-absorption enhancers (meat or vitamin C-rich foods) at each meal and the consumption of iron inhibitors (tea, coffee, milk) were discouraged at and for one hour after lunch and dinner. Blood tests and 7-day weighed food records were obtained at baseline and repeated after the 12-week intervention and again after a 6-month follow-up phase.

Iron status was found to improve in both the diet and supplement groups during the intervention. Serum ferritin values changed over time in both intervention groups. Mean serum ferritin in the supplement group increased by 15.8 micrograms/L from baseline to the end of the 12-week intervention but then remained stable at the 6-month follow-up. In the diet group, serum ferritin increased by 2.1 micrograms/ L during the intervention period and then increased an additional 4.2 micrograms/L during follow-up. There was found to be a significant increase in mean hemoglobin during the intervention in the supplement group, but not in the diet group. However, there were no significant differences in mean hemoglobin between the two groups at 12 weeks or at follow-up. Despite the improvements in iron-status indicators of subjects in the diet group, no significant changes in mean dietary intakes of heme iron, or enhancers or inhibitors were found during the dietary trial. Mean compliance in the diet group was lower than mean compliance in the supplements group.

The investigators believe the results of this study suggest that dietary treatment of iron deficiency is feasible for women of childbearing age and may result in long-term dietary modifications, which was suggested by the continued improvements in iron status during the follow-up phase. The iron supplement increased serum ferritin concentrations more quickly, however dietary intervention likely has less of the marked side effects reported with iron supplement use.

A. Patterson, W. Brown, D. Roberts, et al. Dietary treatment of iron deficiency in women of childbearing age. American Journal of Clinical Nutrition 74: 650-656 (November 2001). [Correspondence: A. J. Patterson, Research Center for Gender and Health, The University of Newcastle, University Drive, Callaghan, New South Wales 2308, Australia. E-mail: whajp@alinga.newcastle.edu.au.]