One very important vitamin that an expectant mother is Folic Acid. Supplementing folic acid prior to conception to early pregnancy reduces the risk of having a child with serious birth defects, such as Spina Bifida, an incomplete closure of the spinal cord and spinal column. Anencephaly, severe under development of the brain. Encephalocele, when brain tissue protrudes out to the skin from an abnormal opening in the skull.
If a mother does not get adequate amounts of certain nutrients (such as Vitamin B6, Vitamin B12 or iodine), it can decrease nutrient levels in her milk. However, it is usually only a problem in areas of malnutrition. The best solution in such cases is to improve or supplement the mothers diet.
For instance, mothers who are cutting on calories such as those who get 2,200 calories daily may need extra calcium, zinc, magnesium, thiamine (Vitamin B1), Vitamin B6 and Vitamin E. On the other hand, mothers who get 1,800 calories daily may need extra calcium, zinc, magnesium, thiamine (Vitamin B1), Vitamin B6, Vitamin E, folic acid, riboflavin (Vitamin B2), phosphorus and iron.
Mothers who eat no animal products or are otherwise at risk for Vitamin B12 deficiency need to get adequate amounts of Vitamin B12 from supplements or fortified foods. Mothers who have little exposure to sunlight need to get adequate amounts of Vitamin D from supplements of Vitamin D-rich foods.
In addition, research has shown that expectant mothers who supplement with water-soluble vitamins (e.g., Vitamin B and Vitamin C) usually increase their breast milk levels.