Mother's milk provides almost complete diet to the new-born, but it lacks the following

Question

UnlockIAS · Accepted Answer

Correct — A, Iron. Human breast milk is close to a complete food for the first six months: it supplies proteins (whey-dominant lactalbumin plus casein), lactose, fats with essential fatty acids, all the major minerals in a form an infant's kidneys can handle, and a package of protective factors — secretory IgA, lactoferrin, lysozyme and live cells — that no substitute reproduces. The one mineral it is conspicuously poor in is iron. A healthy full-term baby manages anyway for two reasons: it is born with a store of iron laid down in the liver during the last trimester of pregnancy, and the small amount of iron in breast milk is bound to lactoferrin and absorbed far more efficiently than the iron in cow's milk or in formula. Those stores are, however, finite — they run low at roughly four to six months, which is exactly why complementary feeding starts at six months and why India's infant nutrition programmes push iron supplementation for young children. Calcium, magnesium and potassium are all present in adequate, well-absorbed amounts, so iron is the only defensible answer.

Why the other options are wrong — (b) Breast milk supplies calcium in a highly bioavailable form, and the rapid bone growth of the first months runs on it. Its calcium concentration is lower than cow's milk, but the fraction actually absorbed is much higher — low concentration is not the same as deficiency, and calcium deficiency is not a recognised problem in exclusively breastfed term infants.  (c) Magnesium is present in adequate quantity; dietary magnesium deficiency in an exclusively breastfed, healthy term infant is not a described clinical problem. Candidates pick it only because magnesium is the least familiar mineral on the list.  (d) Breast milk is a good potassium source — its potassium clearly exceeds its sodium, an electrolyte balance suited to the immature infant kidney. Nothing about breastfeeding creates a potassium gap.

Concept: Breast milk changes as lactation proceeds: colostrum in the first few days is thick, yellow and loaded with immunoglobulins and other immune factors; it gives way to transitional and then mature milk, which is higher in fat and lactose. Mature milk delivers energy, protein, fat, lactose, calcium, magnesium, potassium, sodium and most vitamins in proportions tuned to the infant. The recognised gaps are iron (and, in most populations, vitamin D). WHO and the Government of India therefore advise exclusive breastfeeding for the first six months, followed by nutritionally adequate complementary feeding with breastfeeding continued up to two years or beyond.

State PCS 2019 Q92 — Science & Technology PYQ with Answer

State PCS 2019 Q92 — Science & Technology PYQ with Answer