Poor zinc status in early infancy among both low and normal birth weight infants and their mothers in Delhi.

BACKGROUND

Low birth weight (LBW) infants are at high risk of zinc deficiency, but there is a paucity of data on their zinc status.

OBJECTIVE

To evaluate zinc status of LBW (BW <2,500 g) and normal birth weight (NBW; BW ≥ 2,500 g) infants at birth and in early infancy.

METHODS

A total of 339 infants (LBW, n = 220; NBW, n = 119) were enrolled, and venous blood samples of mother-infant dyad were taken within 48 h of birth. Infants' levels were repeated between 2 and 10 months of age. Serum zinc levels were estimated using an inductively coupled plasma mass spectrometer. Primary outcome was zinc deficiency, defined as serum zinc <65 µg/dl.

RESULTS

Zinc results were available for 182 LBW and 103 NBW infants at birth and for 100 LBW and 66 NBW infants at follow-up with a median postnatal age of 14 and 15.5 weeks, respectively. Median zinc levels were low and comparable at birth as well as at follow-up, with zinc deficiency being present in 51.0% of LBW and 42.4% of NBW infants at birth and in 79.0% of LBW and 66.7% of NBW infants at follow-up. Zinc levels decreased significantly in both groups from birth to follow-up, irrespective of zinc multivitamin supplementation. Zinc levels of infants with BW <2,000 g at follow-up were significantly lower compared to infants with higher BW.

CONCLUSION

Zinc status was poor in many infants at birth irrespective of BW. Zinc status worsened significantly during early infancy, with infants with BW <2,000 g having the lowest zinc levels.