Monday, February 26, 2007

MICRONUTRIENT SUPPLEMENTATION IN PREGNANCY

Rebecca Singson, M.D., FPOGS

Pregnancy is in the only time in the life of a woman when another human being becomes a parasite to her, depending on her body to provide the nutrients the fetus needs in order to grow. It is thus a critical time to be equipped with the necessary micronutrients to prevent damage to the growing fetus as well as to the mother herself. Nature protects the fetus so much that if the baby needs a nutrient that the mother does not have enough of for herself and her baby, the nutrient will be preferentially directed to the baby even to the detriment of the mother.

In this generation when we no longer plant our food the way our forefathers did, the nutrition we get from eating fastfood, bottled, canned, frozen food have become devoid of the nutrients we need to keep our bodies healthy, much less to support a healthy pregnancy. We need to insure ingesting at least the following nutrients to begin working towards an uneventful pregnancy.

FOLIC ACID. Folic acid can be found in foods such as spinach, parsley, broccoli, lettuce, lima beans, turnip greens, asparagus and beef liver. Folic acid supplementation is best taken even before planning your pregnancy since there is strong evidence that folic acid can reduce certain birth defects of the brain and spinal cord by more than 70 percent. These birth defects are called neural tube defects (NTDs). NTDs happen when the spinal cord fails to close properly.The most common neural tube defect is spina bifida which occurs when part of the baby's spinal cord remains outside the body. The baby may have paralyzed legs and, later, may develop bladder and bowel control problems. The most serious neural tube defect is anencephaly when baby is born without part of its skull and brain, and eventually dies. For all childbearing ages, the Center for Disease Control in the U.S. recommends that all women of childbearing age take at least 400mg of folic acid daily but for all pregnant women, 1mg/day is recommended. Women with a history a child with neural tube defect should take 4 mg of folic acid 1 month prior to conception and and all throughout the first trimester.1

IRON. According to the Cochrane review, rron supplementation appears to prevent low haemoglobin at birth or at six weeks post-partum.2 The availability or iron for our bodies to use depends on the food source. Heme iron, which is found only in meat, poultry, and fish, is two to three times more absorbable than non-heme iron, which is found in plant-based foods and iron-fortified foods 3.4. The bioavailability of non-heme iron is strongly affected by the kind of other foods ingested at the same meal. Enhancers of iron absorption are heme iron (in meat, poultry, and fish) and vitamin C; inhibitors of iron absorption include polyphenols (in certain vegetables), tannins (in tea), phytates (in bran), and calcium (in dairy products)5.6 . Vegetarian diets, by definition, are low in heme iron but can certainly be increased by careful planning of meals. The CDC recommends taking or low dose 30 mg/day) supplements of iron at the first prenatal visit. In the presence of anemia, treatment involves prescribing an oral dose of 60-120 mg/day of iron.7.

IODINE. This is essential for normal fetal thyroid function. If the mother lacks iodine, the baby may develop cretinsm (congenital hypothyroidism) of which mental retardation is a component. Cretins have abnormal looking faces with the tongue sticking out. Acc. to the Cochrane Review, iodine deficiency is the leading preventable cause of intellectual impairment in the world. Supplementation during pregnancy especially in areas with high incidence of cretinism results in reduction of this problem with no adverse side effects.8

The use of iodized salt is one way to prevent iodine deficiency. Salmon, tuna and seaweeds are excellent leading sources of iodine from food.

If using seaweeds as an iodine source it is best to use seaweeds that have been found to have a fairly consistent iodine content, such as kelp (kombu) or hijiki. It may be dangerous to consume more than 100g/year (by dried weight) of most seaweeds carries a significant risk of thyroid disorder due to iodine intakes in excess of 1000 micrograms per day.

Nori (the seaweed used to wrap sushis with) is low in iodine and several sheets a day can be eaten without any concern about excess iodine. Frequent addition of small amounts of powdered or crumbled seaweed to stews or curries while cooking, or to other foods as a condiment, is an excellent way to provide adequate iodine (in the absence of other supplementation) . 100g of dried hijiki or 15g of dried kombu or kelp in a convenient container in the kitchen provides one year's supply for one person.

MAGNESIUM. Magnesium supplementation during pregnancy has been associated with fewer pre-term births and less intrauterine growth retardation. 9.10,11 Magnesium deficiency is associated with pre-eclampsia, and pre-term delivery and possibly with low birth weight.12 , coagulation defects 13, premature delivery14,15, intrauterine growth retardation 9.15,and muscle cramping16 Diets high in magnesium density would contain whole grains, lean meats, low amounts of fats and sugars, abundant fruits and vegetables, and low-fat milk. Diets low in magnesium density would contain refined cereal grains, fatty meats, high amounts of fats and sugars, few fruits and vegetables and sugar-containing soft drinks.

DHA. In the latest researches it has been found that supplementing pregnant mothers with fish oil may benefit brain and retinal development in their offspring particularly if born prematurely. Supplementing from mid-pregnancy to the 34th week was found to be perfectly safe and more importantly, may reduce the incidence of preeclampsia (pregnancy-related high blood pressure).17 It was found that breastmilk contains DHA whereas formula milk did not. Researchers at the University of Milan report that infants whose formula contains long- chain polyunsaturated fatty acids [especially Docosahexaenoic acid (DHA)] have better brain development than children who do not receive DHA in their formula. The observation supports earlier findings that there is a direct correlation between the DHA concentration in the red blood cells of infants and their visual acuity. The researchers recommend that infants who are not breastfed be fed on a DHA- enriched formula. Nothing is as complete as breast milk since it is already complete with the fatty acids necessary for good brain development.

MICRONUTRIENT INTERACTIONS.

There are some micronutrients that alter the absorption of others. For example, calcium can block the absorption of iron. Vitamin A may also contribute to anemia by interfering with iron although studies have shown that when given together, there is greater reduction in anemia. Iron supplements can also interfere with the absorption of zinc. On the other hand, vitamin C can increase the absorption of and zinc. Zinc in high doses may interfere with absorption of iron or copper. But many studies still document achieving greater benefits with combined, rather than single, micronutrients therapy but many more studies are required to evaluate these interactions in malnourished populations. Because of the possibility that there may be multiple deficiencies in pregnant women in developing countries, UNICEF has concluded that a multivitamin–mineral supplement should be given during pregnancy19. By simply supplementing, many complications in the mother and infant during and after pregnancy may be avoided.

1Centers for Disease Control. Recommendations for the use of folic acid to reduce the number of cases of spina bifida and other neural tube defects. MMWR 1992;41(No. RR-14)
2 Mahomed K. Iron supplementation in pregnancy. The Cochrane Database of Systematic Reviews 1999, Issue 4. Art. No.: CD000117. DOI: 10.1002/14651858.CD000117.
3Hallberg L. Bioavailability of dietary iron in man. Annu Rev Nutr 1981;1:123-47.
4Skikne B, Baynes RD. Iron absorption. In: Brock JH, Halliday JW, Pippard MJ, Powell LW, eds. Iron metabolism in health and disease. London, UK: W.B. Saunders, 1994:151-87. Bothwell TH. Overview and mechanisms of iron regulation. Nutr Rev 1995;53(9):237-45.
5Bothwell TH. Overview and mechanisms of iron regulation. Nutr Rev 1995;53(9):237-45.
6Siegenberg D, Baynes RD, Bothwell TH, et al. Ascorbic acid prevents the dose-dependent inhibitory effects of polyphenols and phytates on nonheme-iron absorption. Am J Clin Nutr 1994;53:537-41.
7Centers for Disease Control. Recommendations for the use of folic acid to reduce the number of cases of spina bifida and other neural tube defects. MMWR April 03, 1998 : 47(RR-3);1-36
8Mahomed K , Gülmezoglu AM. Maternal iodine supplements in areas of deficiency. The Cochrane Database of Systematic Reviews 1997, Issue 4. Art. No.: CD000135. DOI: 10.1002/14651858.CD000135
9Conradt A, Weidinger H and Algayer H. Magnesium therapy decreased the rate of intrauterine fetal retardation, premature rupture of membranes and premature delivery in risk pregnancies treated with betamimetics Magnesium 4, 20-28, 1985.
10Spatling L and Spatling G. Magnesium supplementation in pregnancy: a double blind study British Journal of Obstetrics and Gynecology 95, 120-, 1988.
11Sibai BM, Villar L and Bray E (1989) Magnesium supplementation during pregnancy. A double-blind randomized controlled clinical trial American Journal of Obstetrics and Gynecology 161, 115-119.
12Chien PFW, Khan KS and Arnott N (1996) Magnesium sulphate in the treatment of eclampsia and pre-eclampsia: an overview of the evidence from randomized trials British Journal of Obstetrics and Gynecology 103, 1085-1091.
13Weaver, K.: A possible anticoagulant effect of magnesium in preeclampsia; in Cantin, Seelig, Magnesium in health and disease, pp. 833-838 (Spectrum Press, New York 1980).
14Conradt, A.; Weidinger, H.; Algayer, H.: Magnesium therapy decreased the rate of intrauterine fetal retardation, premature rupture of membranes and premature delivery in risk pregnancies treated with betamimetics. Magnesium 4: 20-28 (1985).
15Kuti, V.; Balazs, M.; Morvay, F.; Varenka, Z.; Székely, A.; Szücs, M.: Effect of maternal magnesium supply on spontaneous abortion and premature birth and on intrauterine foetal development: experimental epidemiological study. Magnesium- Bull. 3: 73-79 (1981).
16Hunt, S.M.; Schofield, F.A.: Magnesium balance and protein intake level in adult human female. Am. J. clin. Nutr. 22: 367-373 (1969).
17Connor, William E., et al. Increased docosahexaenoic acid levels in human newborn infants by administration of sardines and fish oil during pregnancy. Lipids, Vol. 31 (suppl), 1996, pp. S183- S87
18Agostoni, Carlo, et al. Docosahexaenoic acid status and developmental quotient of healthy term infants. The Lancet, Vol. 346, September 2, 1995, p. 638
19UNICEF (1999) Composition of a multi-micronutrient supplement to be used in pilot programmes among pregnant women in developing countries.


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