Infant nutrition

Originally published in The Ottawa Citizen January 15, 2002

Many new parents have questions about infant nutrition. Do infants require any nutritional supplements? Are there different considerations for breastfed and bottle-fed babies?

Several nutrients essential to proper growth and development may require supplementing — for example, vitamin D and iron.

Normal infant and child bone growth requires a steady supply of calcium and phosphate. Vitamin D promotes the intestinal absorption of calcium and, to a lesser extent, phosphorus. Lack of vitamin D will lead to reduced blood levels of calcium. The body, in order to maintain a normal blood level, will break down or demineralize bone to release the calcium leading to osteoporosis in adults and rickets in children. Indeed, the bones function as a calcium reservoir.

The incidence of infant vitamin D deficiency rickets is increasing in Canada. The Canadian Pediatric Surveillance Program reported 51 confirmed cases from July 2002 to June 2003.

The first sign of rickets occurs in areas of rapid bone growth: the knee, the distal forearm (where the forearm meets the wrist) and rib cage. Each of the ribs on the front of the rib cage near the breastbone will have a noticeable bump or lump of bone. Indeed, it will appear as a line of beads running top to bottom along the rib cage.

The wrists will become enlarged and the forearm will appear bowed. The legs will also bow outward.

The sides of the skull will soften and the forehead will appear sunken and small. The closing of the skull’s fontanelles, or soft areas, will be delayed.

The areas affected will depend on the child’s age. The crawling infant will have deformities of the wrist and forearm, whereas the toddler will demonstrate bowed legs.

Rickets can cause a reduction in muscle tone leading to delayed motor development milestones. Severely low calcium levels can lead to seizures. These children are also prone to infectious diseases.

Most are breastfed infants not receiving vitamin D supplements. Breast milk is not a rich source of vitamin D. Sunlight exposure, food (fortified milk, fatty fish, cod-liver oil, and eggs) and infant formula are sources of vitamin D. The Canadian Pediatric Societies recommends breastfed infants receive a daily supplement of oral vitamin D (Di-vi-sol).

Breast milk is the optimal nutritional source for term infants during their first year of life, and provides adequate amounts of calcium and phosphorus. Infants exclusively breastfed during the first six months after birth and supplemented with solid food between six and 12 months of age will receive adequate amounts of these minerals, resulting in appropriate bone mineralization.

Dietary iron is required for proper development of the infant nervous system. Many infants do not get enough iron in their diets. Indeed, low-iron infant formulas generate 30 per cent of sales in Canada. These formulas increase the risk of iron deficiency anemia.

Dr. David Mack, head of pediatric gastroenterology at CHEO, notes: “Public health policy successes include the introduction of iron-fortified infant formulas in the 1970s with the prevalence of iron-deficiency anemia being dramatically reduced, but Canadian infants and children are still at risk.”

This anemia, or reduction of oxygen-transporting red blood cells, reduces the delivery of oxygen to the developing infant, especially the brain and nervous system. Iron-deficiency anemia is associated with problems in cognitive, behavioural and physical development in infants and children.

In 1999, the journal Pediatrics published a paper indicating that the rate of iron-deficiency anemia in nine-month-olds fed low-iron formula was 28 to 38 per cent even with iron-supplemented foods. The rate plummeted to 0.6 per cent with iron-fortified formula use.

There are no known medical contraindications to using iron-fortified formulas. They do not cause constipation. Professional organizations do not advocate using low-iron formulas. Even the formula company representatives discourage its use.

Some parents continue with low-iron based formulas because hospitals stock and distribute them to parents for newborn feeds. Looking for reasons why low-iron formula use is so common reveals few answers. There is no scientific evidence to support these products.

Breastfed infants will require some form of iron supplement after four to six months of age. An average of two ounces of iron-fortified cereal per day is sufficient to meet an infant’s daily iron requirement. The iron drops, Fer-in-Sol, can be administered if the infant does not eat enough cereal to meet his or her needs of one milligram per kilogram per day.

Discuss with your doctor when is the best time to begin infant vitamin D and iron supplementing. They are an inexpensive and important means of maximizing your infant’s growth and development.

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