Vitamin A Supports Immune Health

BISSAU, Guinea—Providing children with vitamin A supplementation prior to vaccination against tuberculosis may enhance the immune system’s response, according to a new study (Am J Clin Nutr. 2007;86(4):1152-9).

Researchers in Guinea-Bissau examined the effects of simultaneously administering the Bacille Calmette Guerin (BCG) vaccine and vitamin A supplementation (VAS). The study was conducted among 2,710 infants who were randomly given either 50,000 IU vitamin A or placebo, along with the BCG vaccine, at birth. They were later examined for BCG scar formation and delayed-type hypersensitivity (DTH) to purified protein derivative of Mycobacterium tuberculosis (PPD) at two and six months of age.

At two months, 39 percent of infants responded to PPD (43 percent of the boys and 34 percent of the girls). The measurable PPD reaction for VAS compared to placebo recipients was 0.90 for all infants, 0.81 for boys and 1.04 for girls. At six months of age, the results showed 42 percent of all infants responded to PPD, with no difference between the VAS and placebo recipients.

The researchers concluded administering VAS in conjunction with the BCG vaccine does not influence the long-term response to BCG. It does, however, temporarily alter the DTH reaction to PPD among boys at two months, suggesting sex differences in the immunologic response to VAS given in combination with BCG.