Wednesday, May 24, 2017

Iron During Pregnancy and Lactation

Reference from the joint report of FAO/WHO expert consultation on Human Vitamins and Minerals verbatim.




Iron during pregnancy and lactation

94. Hallberg, L. 1988. Iron balance in pregnancy. In: Berger H, ed. Vitamins and minerals in pregnancy and lactation. p. 115-127. Nestlé Nutrition Workshop Series Vol 16. New York: Raven Press.

95. Hallberg, L. 1992. Iron balance in pregnancy and lactation. In: Fomon SJ., Zlotkin S, eds. Nutritional anemias. New York: Raven Press, Ltd. p.13-25. Nestlé Nutrition Workshop Series, vol 30).

Effects of Iron Deficiency

Reference from the joint report of FAO/WHO expert consultation on Human Vitamin and Minerals verbatim.

3. Dallman, P.R. 1986. Biochemical basis for the manifestations of iron deficiency. Ann.
Rev. Nutr., 6: 13-40.

82. Egderton, V.R. 1972. Iron deficiency anemia and physical performance and activity of
rats. J. Nutr., 102: 381-400.

83. Finch, C.A. , 1976. Iron deficiency in the rat. Physiological and biochemical studies of
muscle dysfunction. J. Clin. Investig., 58: 447-53.
Studies in animals have clearly shown that iron deficiency has several negative effects on important functions in the body (3). Physical working capacity in rats has been shown to be significantly reduced in iron deficiency, that is especially valid for endurance activities (82, 83).

Causes of Iron Deficiency

Reference from the joint report of FAO/WHO expert consultation on Human Vitamins and Minerals verbatim.
Nutritional iron deficiency implies that the diet cannot cover physiologic iron requirementsWorldwide this is the most common cause of iron deficiency. In many tropical countries, infestations with hookworms lead to intestinal blood losses that may be considerable. The severity of the infestations with hookworms varies considerably between subjects and regions. The average blood loss can be well estimated by egg counts in stools. Usually the diet in these populations is also limited with respect to iron content and availability.

Indicators of Iron Deficiency

Reference from the joint report of FAO/WHO expert consultation on Human Vitamin and Minerals verbatim.

70. Hallberg, L. 1993. Screening for iron deficiency: an analysis based on bone-marrowexaminations and serum ferritin determinations in a population sample of women. Br. J. Haematol., 85: 787-798.
The absence of iron stores (iron deficiency) can be diagnosed by showing that there is no stainable iron in the reticuloendothelial cells in bone marrow smears or more easily by a low concentration of ferritin in serum (≤15 μg/l). Even if an absence of iron stores per se may not necessarily be associated with any immediate adverse effects, it is a reliable and good indirect indicator of iron-deficient erythropoiesis and of an increased risk of a compromised supply of iron to different tissues. Even before iron stores are completely exhausted, the supply of iron to the erythrocyte precursors in the bone marrow is compromised, leading to iron-deficient erythropoiesis (70).

Iron Deficiency

Reference from the joint report of FAO/WHO expert consultation on Human Vitamins and Minerals verbatim.

Populations at risk for iron deficiency

Worldwide, the highest prevalence of iron deficiency is found in infants, childrenadolescents, and women of childbearing age, especially pregnant women. The weaning period in infants is especially critical because of the very high iron requirements in relation to energy requirements. Thanks to better information and access to fortified cereals for infants and children, the iron situation has markedly improved in these groups in most industrialized countries where the highest prevalences of iron deficiency today are observed in menstruating and pregnant women and adolescents of both sexes.

Enhancement of Iron Absorption

Reference from the joint report of FAO/WHO expert consultation on Human Vitamins and Minerals verbatim.

34. Siegenberg, D. 1991. Ascorbic acid prevents the dose-dependent inhibitory effects of polyphenols and phytates on nonheme-iron absorption. Am. J. Clin. Nutr., 53: 537-41.

51. Cook, J.D. & Monsen, E.R. 1977. Vitamin C, the common cold and iron absorption. Am. J. Clin. Nutr., 30: 235-241.

52. Hallberg, L., Brune, M. & Rossander, L. 1986. Effect of ascorbic acid on iron absorption from different types of meals. Studies with ascorbic-acid-rich foods and synthetic ascorbic acid given in different amounts with different meals. Hum. Nutr: Appl. Nutr., 40: 97-113.

53. Derman, D.P. 1980. Importance of ascorbic acid in the absorption of iron from infant foods. Scand. J. Haematol., 25: 193-201.

54. Hallberg, L., Brune, M. & Rossander-Hultén, L-S. 1987. Is there a physiological role of vitamin C in iron absorption? Ann. York. Acad. Sci., 498: 324-332.
Ascorbic acid is the most potent enhancer of non-heme iron absorption (34, 51-53). Synthetic vitamin C increases the absorption of iron to the same extent as the native ascorbic acid in fruits, vegetables, and juices. The effect of ascorbic acid on iron absorption is so marked and essential that this effect could be considered as one of vitamin C’s physiologic roles (54).

Inhibition of Iron Absorption

Reference from the joint report of FAO/WHO expert consultation on Human Vitamins and Minerals verbatim.

29. Gillooly, M. 1983. The effect of organic acids, phytates and polyphenols on absorption of iron from vegetables. Br. J. Nutr., 49: 331-342. 

30. Hallberg, L., Brune, M. & Rossander, L. 1989. Iron absorption in man: ascorbic acidand dose-dependent inhibition by phytate. Am. J. Clin. Nutr., 49: 140-144.