By Julia Bird
The first thousand days of a child’s life–from just before conception until its second birthday–are a critical time for development. During this period, good nutrition is essential for normal growth. Which nutrients are most important to help children reach their potential?
Pre-Conception and Pregnancy
To ensure the best start in life, the months before pregnancy occurs are important in preparing women for the extra demands during gestation. Women should aim to have a healthy weight, and eat a balanced diet that contains plenty of iron, folic acid, B12, vitamin D, iodine and DHA before they become pregnant [1-3]. Women who start out pregnancy with a healthy body mass index have the lowest risk of pregnancy complications [4, 5]. Women should have sufficient iron stores to carry them throughout pregnancy: not only must women have enough iron to make extra blood for the developing baby, they should also take steps to have adequate iron levels in case of excessive blood loss during labor, delivery or after birth . Women who may become pregnant are advised to consume adequate folic acid. This B vitamin is needed for the normal development of the spinal cord, and deficiency increases risk of neural tube defects . As the spinal cord closes around the sixth week of pregnancy, just as many women are learning they are pregnant, an adequate status should be achieved before conception. DHA is also important in the nervous system which begins to develop around the fifth week of pregnancy .
Once pregnant, women need to eat a healthy diet and make sure their weight gain follows guidelines. Sufficient protein and carbohydrates ensure that the fetus has the energy and building blocks to develop normally. In the second half of pregnancy, the fetal brain enters a rapid phase of growth and development. The long chain omega-3 fatty acid docosahexaenoic acid (DHA) is an essential fat, incorporated into fetal brain and nervous system. DHA supports optimal brain, eye and nervous system development . The biological need for DHA is demonstrated by active delivery through the placenta to the developing baby . Choline is often considered to be a B-vitamin as it is involved in similar processes in the body, although the body can produce choline to at least partially meet needs. Even so, in pregnancy, women transfer much of their choline stores to the fetus, and it is important for them to include choline-rich foods in their diet . A poor vitamin D status is common in many countries and especially in pregnant women. It is important for pregnant women to have an adequate status as vitamin D helps to absorb calcium from foods, and it may help avoid some pregnancy complications. Higher vitamin D levels in pregnant women means that newborns also have a better status, reducing risk of rickets and contributing to long term bone health .
Breast milk is the healthiest option for women and their infants, as it contains antibodies that protect infants against disease, and it encourages better post-delivery healing. As women’s food intakes during lactation need to meet their own needs in recovering from childbirth, and those of their infants, dietary recommendations are increased for many macro- and micronutrients . Breast milk contains considerable amounts of protein and fat, which corresponds to an increased dietary requirement, although maternal stores can be used to buffer against poor intakes. For some nutrients, low maternal stores result in lower breast milk concentrations. With critical nutrients DHA, vitamin A and iodine, the amounts in breast milk reflect maternal status. As babies’ brains grow quickly in size particularly in the first six months of life, lactating women need to consume plenty of DHA to supply enough fatty acids for the growing brain cells . Iodine is essential in thyroid hormones and is therefore needed for normal growth and development. Lactating women need to ensure that their iodine intakes are sufficient for both themselves and their infants . Avoiding vitamin A deficiency is important for lactating women and their infants as vitamin A is required for normal vision and cell division. A low vitamin A status in women translates to low levels of vitamin A in breast milk .
The best food for newborns is breast milk. If a mother is unable to breast feed, an infant formula can be given . A safe water supply must also be available. Breast milk contains the right amount of fat, vitamins and minerals to support human babies’ growth. Infant formula is based on the composition of breast milk with the exception of vitamins D and K. Levels of these vitamins are low in breast milk and breast fed infants should be supplemented to avoid rickets or vitamin K deficiency bleeding. Breast milk always contains the long chain fatty acids arachidonic acid (ARA) and DHA as infants cannot convert these efficiently from shorter chain precursors . Experts in a recent publication recommend that DHA supplementation should be accompanied by at least equal amounts ARA as it is reported to have a positive effect on the maturation of vision and on childhood development .
Infants and Toddlers
Around six months of age, infants should gradually start to receive complementary foods. These foods are initially soft and do not require chewing. Gradually, regular family food can be introduced in steps with the goal of balanced family nutrition composed of three meals a day and two snacks in between . By the time infants reach their second year, adult foods should make up the bulk of a toddler’s diet.
Early childhood is an important time when healthy eating patterns must be established. Sources of iron, vitamin D and DHA are sometimes limited in the diets of toddlers . Iron is an important nutrient for infants in the second half of their first year of life. Worldwide, the toddler years are those that carry the greatest risk of iron deficiency. As toddlers may not be able to chew well, it can be difficult for them to eat the most bioavailable form of iron from meat, although some toddlers may enjoy it. Iron-fortified cereals may be a good choice. Many countries recommend that toddlers are given vitamin D supplements as this vitamin is difficult to obtain enough from the diet or from sunlight exposure due to the risk of sensitive young skin getting sunburnt. Vitamin D helps toddlers build strong bones. Fatty fish such as sardines, salmon and mackerel are the primary source of DHA. In many countries toddlers eat very little fish resulting in a shortfall in their intake of DHA during a rapid period of brain development. DHA fortified foods and age-appropriate supplements may be helpful in making up the DHA gap.