The relative bioavailability in humans of elemental iron powders for use in food fortification
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Bioavailability data in humans of elemental iron powders is limited although elemental iron is a common form of iron when used as a fortificant.
Aim of the study
The relative bioavailability (RBV) of seven elemental iron powders, five commercially available and two developmental are evaluated. In addition, one commercial electrolytic iron powder given with ascorbic acid (AA) was examined.
Based on a validated method this double–blinded randomized crossover study included three groups of male blood donors (n = 3*16) who were served rolls fortified with different elemental iron powders or ferrous sulfate (FeSO4) nine weeks apart. Blood samples were drawn every hour for six hours. RBV was obtained by comparing the increase in serum iron concentration induced by the elemental iron with the increase induced by FeSO4.
All elemental iron powders studied were significantly less well absorbed compared to FeSO4. The electrolytic iron given with 50–mg AA was as well absorbed as FeSO4 (molar ratio = 1:6, AA:Fe). The mean RBVs of the iron powders were: electrolytic (A–131, RBV = 0.65); electrolytic (Electrolytic, RBV = 0.59); carbonyl (Ferronyl, RBV = 0.58); H–reduced (AC– 325, RBV = 0.56); H–reduced (Hi–Sol, RBV = 0.50); carbonyl (CF, RBV = 0.37); reduced (Atomet 95SP, RBV = 0.36). The reduced iron was distinguished by having significantly lower RBV (0.36) although no significant overall ranking was possible.
Based on a validated method this doubleblinded cross–over study in humans showed that the evaluated elemental iron powders currently available for commercial use are significantly less well absorbed compared to FeSO4. The results indicate that the reduced iron powder was absorbed to a lower extent compared to the other iron powders and only 36% compared to FeSO4. Ascorbic acid seems to improve the bioavailability of elemental iron even though a rather low molar ratio is used. Thus, if confirmed, this enhancing effect of ascorbic acid on elemental iron when used as a fortificant could be used by co–fortifying them.
Key wordsserum iron ferrous sulfate elemental iron compound iron absorption
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- 1.Hurrell R, Bothwell T, Cook JD, Dary O, Davidsson L, Fairweather-Tait S, Hallberg L, Lynch S, Rosado J, Walter T, Whittaker P (2002) The usefulness of elemental iron for cereal flour fortification: a SUSTAIN Task Force report. Sharing United States Technology to Aid in the Improvement of Nutrition. Nutr Rev 60:391–406Google Scholar
- 2.Forbes AL, Arnaud MJ, Chichester CO, Cook JD, Harrison BN, Hurrell RF, Kahn SG, Morris ER, Tanner JT, Whittaker P, et al. (1989) Comparison of in vitro, animal, and clinical determinations of iron bioavailability: International Nutritional Anemia Consultative Group Task Force report on iron bioavailability. Am J Clin Nutr 49:225–238Google Scholar
- 3.Hallberg L, Brune M, Rossander L (1986) Low bioavailability of carbonyl iron in man: studies on iron fortification of wheat flour. Am J Clin Nutr 43:59–67Google Scholar
- 4.Bjorn-Rasmussen E, Hallberg L, Rossander L (1977) Absorption of ‘fortification’ iron. Bioavailability in man of different samples of reduced Fe, and prediction of the effects of Fe fortification. Br J Nutr 37:375–388Google Scholar
- 5.Cook JD, Minnich V, Moore CV, Rasmussen A, Bradley WB, Finch CA (1973) Absorption of fortification iron in bread. Am J Clin Nutr 26:861–872Google Scholar
- 6.Hoglund S, Reizenstein P (1969) Studies in iron absorption. V. Effect of gastrointestinal factors on iron absorption. Blood 34:496–504Google Scholar
- 7.Rios E, Hunter RE, Cook JD, Smith NJ, Finch CA (1975) The absorption of iron as supplements in infant cereal and infant formulas. Pediatrics 55:686–693Google Scholar
- 8.Motzok I, Verma RS, Chen SS, Rasper J, Hancock RG, Ross HU (1978) Bioavailability, in vitro solubility, and physical and chemical properties of elemental iron powders. J Assoc Off Anal Chem 61:887–893Google Scholar
- 10.Swain JH, Newman SM, Hunt JR (2003) Bioavailability of elemental iron powders to rats is less than bakery-grade ferrous sulfate and predicted by iron solubility and particle surface area. J Nutr 133:3546–3552Google Scholar
- 12.Reddy MB, Cook JD (1991) Assessment of dietary determinants of nonhemeiron absorption in humans and rats. Am J Clin Nutr 54:723–728Google Scholar
- 13.Ekenved G, Norrby A, Solvell L (1976) Serum iron increase as a measure of iron absorption – studies on the correlation with total absorption. Scand J Haematol 28(Suppl):31–49Google Scholar
- 14.Hoppe M, Hulthén L, Hallberg L (2003) Serum iron concentration as a tool to measure relative iron absorption from elemental iron powders. Scand J Clin Lab Invest 63:489–496Google Scholar
- 16.SUSTAIN (2001) Guidelines for Iron Fortification of Cereal Food Staples. Washington, DC (Accessed Dec 16 2004). In: p www. sustaintech. org/ pub2. pdfGoogle Scholar
- 17.SUSTAIN (2004) Evaluation of the Bioavailability of Elemental Iron Powders Used for Food Fortification (Accessed Dec 162004). In: p www. sustaintech. org/pub1. pdfGoogle Scholar
- 18.(1971) International committee for standardization in hematology. Proposed recommendations for measurement of serum iron in human blood. Br J Haematol 20:451–453 Google Scholar
- 19.Bothwell TH, Pirzio-Biroli G, Finch CA (1958) Iron absorption. I. Factors influencing absorption. J Lab Clin Med 51:24–36Google Scholar
- 20.Smith MD, Pannacciulli IM (1958) Absorption of inorganic iron from graded doses: its significance in relation to iron absorption tests and mucosal block theory. Br J Haematol 4:428–434Google Scholar
- 21.Bonnet JD, Hagedorn AB, Owen CA Jr (1960) A quantitative method for measuring the gastrointestinal absorption of iron. Blood 15:36–44Google Scholar
- 22.Werner E, Kaltwasser JP, Ihm P (1977) Oral iron treatment: intestinal absorption and the influence of a meal (author’s transl). Dtsch Med Wochenschr 102:1061–1064Google Scholar
- 23.Hallberg L, Bjorn-Rasmussen E, Ekenved G, Garby L, Rossander L, Pleehachinda R, Suwanik R, Arvidsson B (1978) Absorption from iron tablets given with different types of meals. Scand J Haematol 21:215–224Google Scholar
- 24.Wheby MS, Umpierre G (1964) Effect of transferrin saturation on iron absorption in man. N Engl J Med 271:1391–1395Google Scholar
- 25.Fawwaz RA, Winchell HS, Pollycove M, Sargent T (1967) Hepatic iron deposition in humans. I. First-pass hepatic deposition of intestinally absorbed iron in patients with low plasma latent ironbinding capacity. Blood 30:417–424Google Scholar
- 26.Younes M, Trepkau HD, Siegers CP (1990) Enhancement by dietary iron of lipid peroxidation in mouse colon. Res Commun Chem Pathol Pharmacol 70:349–354Google Scholar
- 27.Lund EK, Fairweather-Tait SJ, Wharf SG, Johnson IT (2001) Chronic exposure to high levels of dietary iron fortification increases lipid peroxidation in the mucosa of the rat large intestine. J Nutr 131:2928–2931 Google Scholar
- 28.Lund EK, Wharf SG, Fairweather-Tait SJ, Johnson IT (1999) Oral ferrous sulfate supplements increase the free radical- generating capacity of feces from healthy volunteers. Am J Clin Nutr 69:250–255Google Scholar
- 30.Walter T, Dallman PR, Pizarro F, Velozo L, Pena G, Bartholmey SJ, Hertrampf E, Olivares M, Letelier A, Arredondo M (1993) Effectiveness of iron-fortified infant cereal in prevention of iron deficiency anemia. Pediatrics 91:976–982 Google Scholar
- 31.Lynch SR, Stoltzfus RJ (2003) Iron and ascorbic acid: proposed fortification levels and recommended iron compounds. J Nutr 133:2978S–2984SGoogle Scholar