During the first 6 months of life, infants use iron liver reserves build up during fetal life, as the iron content of breast milk is very low. Thus, at around 6 months, an exogenous source of iron from the diet is needed to meet the nutritional requirements. From 0 to 6 months of life iron requirements are 0.3 mg/day and from 6 to less than 12 months of age, 6 to 11 mg/day, whereas from 12 to less than 36 months the requirements range from 3.9 to 9 mg/day. Iron deficiency can affect brain, neurological, and psychomotor development. Iron deficiency causes a reduced oxygen-carrying capacity, which results in a limited conversion to glucose needed for growth and development. But unlike what happens with neurological development, these limitations can be overcome by iron treatment.
• Calcium and Phosphorus
During the first year of life, bone mineralization and calcium accretion are greatest. It has been suggested that the calcium to phosphorus ratio (Ca:P) is important for bone growth and development during infancy. It is believed that bone mass accumulation in infancy is essential for the prevention of poor childhood growth and adult osteoporosis. In breast milk, the Ca:P is approximately 2:1, with similar ratios in infant formulae. However, absolute quantities are higher in infant formulae to account for the differing bio‐availabilities. Breast milk calcium levels remain constant over the first year; however, the phosphorus content decreases over the course of lactation.
• Vitamin D
Vitamin D is also important during phases of rapid growth and bone mineralization as in infancy, to ensure optimal calcium balance. Exclusively breastfed infants receive below the minimum recommended intake of vitamin D. To avoid possible pathologies derived from the deficit of this vitamin, such as inadequate bone mineralization or rickets, the American Academy of Pediatrics recommends maternal supplementation with 400 to 2000 IU per day to increase levels of vitamin D in breast milk. Vitamin D nutritional requirements from 0 to less than 36 months of life are 10 mg/day. Even though sunlight on the skin enables the body to make vitamin D, exposing your baby’s skin to the sun can be harmful. Once your baby is weaned from breastmilk, talk to your baby’s doctor about whether your baby still needs vitamin D supplements. Some children do not get enough vitamin D from the food they eat.
• Vitamin B12 and folic acid
Folic acid (the synthetic and most stable form of folate, also named Vitamin B9) and Vitamin B12 (cobalamin) play an essential role in central nervous system metabolism and maintenance. It is well known that folic acid deficiency during pregnancy results in higher risk of neural tube defects in the baby. In children, folic acid deficiency is related to impaired cognitive development and increased diarrheal and respiratory disease. During the first 6 months of life, vitamin B12 requirements are 0.4 mg/day and from 6 to less than 12 months 0.5 to 0.8 mg/day, whereas from 12 to less than 36 months are 0.6 to 1mg/day. Folate nutritional requirements, from 0 to 6 months are 65 mg/day, and an adequate intake of 80 mg/day is recommended by EFSA for infants aged 6– 12 months, whereas from 12 to less than
36 months the requirements are 100 mg/day. The upper intake level has been established between 200 and 800 mg of folic acid /day for children aged 1–17 years.