COMPOSITION OF BREAST MILK

Constituents

Level present in breast milk

Total solid %

12.50

Energy   Kilocalories
              Kilojoules

70
291

Protein %

1.03

Lipid %

4.38

Carbohydrate %

6.89

Ash %

0.20

Calcium (mg)

32

Iron (mg)

0.03

Magnesium (mg)

3

Phosphorous (mg)

14

Potassium (mg)

51

Sodium (mg)

17

Zinc (mg)

0.17

Ascorbic acid (mg)

5

Thiamine (mg)

20

Riboflavin (mg)

0.036

Niacin (mg)

0.177

Pantothenic acid

0.223

Vitamin B6 (mg)

10

Folacin (mg)

5

Vitamin B12 (mg)

0.045

Vitamin A (mg)

58

Vitamin D (mg)

0.04

Vitamin E (mg)

0.34

Vitamin C (mg)

4

Breast Milk Proteins

The composition of breast milk consists of protein, fat and lactose and other minerals and vitamins. The protein is present at lower level than the fat component in human milk.

Lactoferrin is an iron binding glycoprotein that exists in cow milk at the level of 0.2 mg per ml. Breast milk contains a higher concentration of lactoferrin at 0.1 to 0.2 g per 100 ml.

It shows antibacterial activity towards Escherichia coli thus warding of intestine, a potential predator. The bacteriostatic effect of lactoferrin may be explained by its ability to bind with iron and thereby preventing its availability to the iron requiring bacteria, there by preventing their growth.

Breast milk also contains a higher concentration of unsaturated Vitamin B12 binding protein, which competes with bacteria requiring Vitamin B12 for their growth.