Vitamins are essential to life, and because the body does not synthesize them, they are a required part of your diet. The food you eat is the best source of nutrients, but pregnant women require extra amounts of certain vitamins, such as folic acid, and supplementation may be required. A well-balanced diet does not put you at risk for overdosing on any vitamin. Supplementation with the fat-soluble vitamins A, D and E, which are stored in the tissues, can have toxic side effects if consumed in amounts that exceed the recommended dietary allowance.
Vitamin A is required for growth, reproduction and healthy skin. In addition, it is a component of the visual pigments of the rod and cone cells in your and your baby’s eyes. A healthy diet that includes yellow and dark green vegetables and fruits meets the recommended dietary allowance for this vitamin, which is 770mcg per day. The upper limit for this vitamin is 3,000mcg per day. Amounts exceeding this can cause congenital malformations, or birth defects, in the developing fetus.
Vitamin D acts as a hormone in your body, regulating your blood levels of calcium and phosphorus. Both vitamin D2, found in plants, and vitamin D3, found in animal tissues, are sources of preformed vitamin D, and vitamin D is also produced in your skin on exposure to sunlight. Vitamin D is the most toxic of all vitamins, and intakes that exceed 100mcg per day can cause loss of appetite, nausea, thirst and stupor and can adversely impact your baby’s health.
Vitamin E is an important antioxidant, and vegetable oils, including oils present in whole foods such as leafy greens, are rich sources of this vitamin. Deficiencies are rarely seen, and supplementation is usually not necessary to achieve the recommended dietary intake of 15mg per day. Vitamin E is the least toxic of the fat-soluble vitamins, and potential benefits outweigh the possibilities of harm. If you choose to take a multivitamin during pregnancy, avoid one that exceeds the RDA of the fat-soluble vitamins.