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ARS Home » Plains Area » Grand Forks, North Dakota » Grand Forks Human Nutrition Research Center » Healthy Body Weight Research » Research » Publications at this Location » Publication #130800


item Swain, James
item Hunt, Janet

Submitted to: Trace Elements in Man and Animals International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 6/2/2002
Publication Date: 5/1/2003
Citation: Swain, J.H., Hunt, J.R. 2003. Bioavailability of elemental iron powders used for food fortification [abstract]. Journal of Nutrition. v.133(5S-1). p.271E.

Interpretive Summary:

Technical Abstract: There is little or no verification of the nutritional efficacy of elemental iron (Fe) powders used widely as food fortificants today. We determined the bioavailability of six commercially-produced elemental Fe powders, collected in 2001 for research by SUSTAIN (Sharing U.S. Technology to Aid in the Improvement of Nutrition). The bioavailability of the Fe powders was smeasured using the AOAC hemoglobin repletion/slope ratio method in 220 weanling, male Sprague-Dawley rats. Following dietary Fe depletion (24 d; approx. 1.5 mg Fe/kg AIN93G diet), the rats' hemoglobin was measured before and after Fe repletion with a diet (14 d; AIN93G diet) fortified with one of the six elemental Fe powders (each approx. 12, 24, and 36 mg Fe/kg), ferrous sulfate (approx. 6, 12, 18, and 24 mg Fe/kg), or no added Fe (approx. 1.5 mg Fe/kg); n=9-10/diet. The bioavailability of the Fe sources (production method, name or grade & source listed), relative to ferrous sulfate (100%), were as follows (slope ratio, 95% CI, different letter indicate differences at p<0.05): Carbonyl (Ferronyl, US), 64 (0.62-0.67) a; Electrolytic, A-131, US, 54 (50-58) b; Electrolytic, India, 46 (43-50) bc; H-reduced, AC-325, US, 42 (37-46) c; Reduced, Atomet95SP, Canada, 24 (20- 28) d; CO-reduced, Sweden, 21 (17-25) d. Although Fe intake and bioavailability influenced both food intake and weight gain, the bioavailability was similar whether based on dietary Fe (mg/kg) or absolute Fe intake (mcg/d)(data not shown). Carbonyl Fe powder was three times more bioavailable than the less expensive CO-reduced and reduced Fe powders. The present findings, together with data on commercial pricing of Fe powders, can assist in developing quantitative recommendations for fortification of foods with specific forms of Fe.