<Ul> <Li> Folic acid supplementation is recommended prior to conception, to prevent development of spina bifida and other neural tube defects . It should be taken as at least 0.4 mg / day throughout the first trimester of pregnancy, 0.6 mg / day through the pregnancy, and 0.5 mg / day while breastfeeding in addition to eating foods rich in folic acid such as green leafy vegetables . </Li> <Li> Iodine levels are frequently too low in pregnant women, and iodine is necessary for normal thyroid function and mental development of the fetus, even cretinism . Pregnant women should take prenatal vitamins containing iodine . </Li> <Li> V itamin D levels vary with exposure to sunlight . While it was assumed that supplementation was necessary only in areas of high latitudes, recent studies of Vitamin D levels throughout the United States and many other countries have shown a large number of women with low levels . For this reason, there is a growing movement to recommend supplementation with 1000 mg of Vitamin D daily throughout pregnancy, vitamin D is necessary to prevent rickets, a disease causing weak bones . </Li> <Li> A large number of pregnant women have been found to have low levels of vitamin B12, but supplementation has not yet been shown to improve pregnancy outcome or the health of the newborn, although there are suspicions . </Li> <Li> Polyunsaturated fatty acids, specifically docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are very beneficial for fetal development . Several studies have shown a small drop in preterm delivery and in low birth weight in mothers with higher intakes . The best dietary source of omega - 3 fatty acids is oily fish . Some other omega - 3 fatty acids not found in fish can be found in foods such as flaxseeds, walnuts, pumpkin seeds, and enriched eggs . </Li> <Li> Iron is needed for the healthy growth of the fetus and placenta, especially during the second and third trimesters . It is also essential before pregnancy for the production of hemoglobin. There is no evidence that a hemoglobin level of 7 grams / 100 ml or higher is detrimental to pregnancy, but it must be acknowledged that maternal hemorrhage is a major source of maternal mortality worldwide, and a reserve capacity to carry oxygen is desirable . According to the Cochrane review conclusions iron supplementation reduces the risk of maternal anaemia and iron deficiency in pregnancy but the positive effect on other maternal and infant outcomes is less clear . </Li> </Ul> <Li> Folic acid supplementation is recommended prior to conception, to prevent development of spina bifida and other neural tube defects . It should be taken as at least 0.4 mg / day throughout the first trimester of pregnancy, 0.6 mg / day through the pregnancy, and 0.5 mg / day while breastfeeding in addition to eating foods rich in folic acid such as green leafy vegetables . </Li> <Li> Iodine levels are frequently too low in pregnant women, and iodine is necessary for normal thyroid function and mental development of the fetus, even cretinism . Pregnant women should take prenatal vitamins containing iodine . </Li> <Li> V itamin D levels vary with exposure to sunlight . While it was assumed that supplementation was necessary only in areas of high latitudes, recent studies of Vitamin D levels throughout the United States and many other countries have shown a large number of women with low levels . For this reason, there is a growing movement to recommend supplementation with 1000 mg of Vitamin D daily throughout pregnancy, vitamin D is necessary to prevent rickets, a disease causing weak bones . </Li>

Explain the factors that affect nutrition in pregnancy