Nutrition in Infancy: Nutritional Requirements

NUTRITIONAL REQUIREMENTS

As growth during infancy is rapid, meeting the nutritional requirements is very important. Nutritional requirements for infants is based on the composition and intake of breast milk of well nourished population combined with the contributions from supplementary foods introduced around 4-5 months of age as mothers milk alone is inadequate after that. The RDA for infants is given in List.

ICMR recommended dietary allowances for Infants

Nutrients 0-6 months 6-12 months

Energy (k.cal) 108 / kg 98 / kg

Protein (gm) 2.05 / kg 1.65 / kg

Calcium (mg) 500 500

Vitamin A

Retinol (mg) or 350 350

B carotene (mg) 1200 1200

Thiamine (mg) 55 / kg 50 / kg

Riboflavin (mg) 65 / kg 60 / kg

Niacin (mg) 710 / kg 650 / kg

Pyridoxine (mg) 0.1 0.4

Ascorbic acid (mg) 25 25

Folic acid (mg) 25 25

Vitamin B12 (mg) 0.2 0.2

1. Energy

The energy recommendations are based on the average secretion of 850 ml of milk per day by a well nourished mother. The infants require 108 k.cal/kg and 98 k.cal/kg during 0-6 months and 6-12 months of age respectively. Of the energy supplied 50 percent is used for basal energy, 25 percent for activity and 25 percent for growth.

Extremely active children may utilize more energy and hence there will not be weight gain unless additional calories are given. After six months 70 percent of energy requirement is met by breast milk and for the rest supplementary foods have to be given.

2. Protein

Protein requirements should not only meet the need for maintenance but also for the rapid skeletal and muscular growth. The human milk provides all the amino acids essential for proper growth. Protein intake of healthy infants during first 6 months of age is 2g/kg body weight. Protein requirement decreases after 6 months as do the energy requirement. After six months the protein requirement is 1.65 g/kg body weight, the contribution being equal from the mothers milk and vegetable protein supplements.

3. Fat

Adequately breast fed infants receive 30g of fat /day of which 10 percent is linoleic acid and 1 percent linolenic acid. Breast milk also meets the essential fatty acid requirements. Foods used as substitutes when breast milk is inadequate or not available should provide this proportion of fat and also ensure that 5-6 percent of energy is in the form of essential fatty acids. During weaning, the diet should provide 25 percent of energy from fat, which should be a blend of visible and invisible fat to reduce bulk.

4. Calcium

Upto 6 months when the infant is solely breast fed 300mg of calcium daily is adequate. Large per cent of calcium in breast milk is retained by infant. As the baby grows, rapid calcification of bones take place which is essential to support the weight of the body by the time the baby walks. To meet these requirements ICMR has recommended 500mg of calcium/day throughout infancy.

5. Iron

The infants require iron for growth, expansion of blood volume and for improving iron stores in the body. Considering the availability and absorption of iron an allowance of 1mg / kg body weight/day for an infant had been recommended. However, the ICMR has not suggested any RDA for iron due to the following reasons

                The infant is born with good iron stores sufficient to last for four months. The haemoglobin level which is about 17g / 100ml at birth falls to 11g/100ml during second week. The released iron from the haemoglobin breakdown is stored in the infant to be used subsequently.

                Though mothers milk contains negligible iron, the amount of bio available iron is sufficient to meet the needs of exclusively breast fed infants.

                Loss of iron in infants is not known correctly and hence the amount to be replaced cannot be assessed.

6. Vitamins

Vitamin A

On the basis of vitamin A ingested by breast fed infants in well nourished communities the ICMR has suggested RDA for vitamin A as 350 mg per day throughout infancy.

Other fat soluble vitamins

ICMR has not recommended any allowance for vitamin D, vitamin E and Vitamin K. The vitamin D requirement placed between 200-400 I.U can be obtained by adequate exposure to sunlight.

B Complex vitamins

RDA for B complex vitamins is expressed in terms of weight of an infant which in reality is based on calorie consumption.

Completely breast fed infants derive the required thiamine and riboflavin requirements from breast milk. ICMR has recommended 55µg/kg body weight and 50 µg/kg body weight of thiamine and 65µg/kg body weight and 60µg/kg body weight of riboflavin during 0-6 months and 6-12 months of age respectively.

Niacin requirements are computed on the same basis as adults i.e., 6.6mg of niacin / 1000 k.cal which when expressed in terms of body weight will be 710 µg/kg and 650 µg/kg body weight for infants 0-6 months and 6-12 months respectively.

Folic acid requirements are based on the folic acid level in breast milk. Breast fed infants normally receive about 25 to 30 µg/kg of folic acid per day most of which is absorbed. Hence the ICMR has recommended folic acid intake of 25µg/day for infants.

It was observed that infants receiving 0.2 µg/kg of vitamin B12/day show normal haemopoiesis whereas those receiving less than 0.05 µg/day exhibit deficiency symptoms. Hence a daily allowance of 0.2 µg of vitamin B12 is recommended.

Vitamin C:

ICMR has recommended an intake of 25mg of vitamin C per day. This allowance is arrived after considering beneficial effect of Vitamin C on non-haem iron absorption.