Vitamins for the first 1000 days: preparing for life.

Vitamins are essential nutrients for many body functions and particularly important during growth. Adequate supply in pregnancy and in early infancy is therefore crucial, but there is still a lack of knowledge about the needed amounts of vitamins of children older than six months and also during pregnancy. Recommendations for intake levels are generally derived by extrapolation from data for infants based in turn on the contents in breast milk and those for adults. A vitamin of particular importance in pregnancy is folic acid due to its role in the development of the brain and nerve system and the prevention of fetal neural tube defects (NTD). Mandatory fortification of flour and certain other grain products in many countries has been associated with a reduction in NTD incidence. However, other deficiencies or suboptimal status of B vitamins, especially B6 and B12 have been repeatedly reported in pregnant women also in high-income countries. Vitamin A is one of the three most critical micronutrients globally and pregnant women and young children are especially vulnerable to deficiencies. Night blindness, anemia, and immunodeficiency are major consequences of inadequate supply in these populations. Much attention has recently been accorded vitamin D that is also critical in pregnant women and young children for instance because of its involvement in bone mineralization but also its more recently discovered immune-modulating function that is thought to prevent development of autoimmune diseases like diabetes mellitus type I. A healthy balanced diet provides the best basis for optimal pregnancy outcome, lactation performance, and complementary feeding. However, supplements or fortified foods may be needed to cover the high requirements especially of critical vitamins such as vitamin D and folic acid and to correct unfavorable dietary patterns in women or to adapt foods to the needs of young children.