New benefits seen in vitamin A therapy.

New benefits seen in vitamin A therapy

Severe vitamin A deficiency can leadto xerophthalmia (dry-eye disease), a leading cause of blindness among children in the developing world. To combat this, world health groups have for years been bringing low-cost eye exams and vitamin A supplements to malnourished regions. But new research indicates that blindness is not this deficiency's only major threat. Even those whose deficiency is not severe enough to cause blindness appear to be at increased risk of infection--a leading childhood killer in developing nations. A new test to diagnose the deficiency along with dramatic increases in child survival where vitamin A therapy was tried, were reported last week at a congressional hearing.

Unpublished Indonesian field studiesof the new eye test indicate that "five to 10 times as many children as previously believed may be suffering ill-effects of vitamin A deficiency--an estimated 25 to 50 million children every year,' says Alfred Sommer, director of the Dana Center of the Wilmer Eye Institute at Johns Hopkins University in Baltimore. Sources of vitamin A include dairy products, carrots and leafy vegetables.

The test, which Sommer helped develop,involves pressing a small strip of filter paper against the white of the eye. If there are mucus-producing goblet cells on the eye's surface, some will adhere to the paper and show up when a stain is applied. The absence of such cells is not only the first symptom of developing xerophthalmia, but also an indicator of otherwise unapparent vitamin A deficiency, explains Keith P. West Jr., a Johns Hopkins nutritionist and collaborator of Sommer's.

In Sumatra, Sommer, West and Indonesiancolleagues achieved striking reductions in childhood mortality through once-every-six-months administration of a high-dose vitamin A capsule. Their study, to be published next month in the AMERICAN JOURNAL OF CLINICAL NUTRITION, involved roughly 26,000 children under age 5--half of whom received no capsules and half of whom were directed to get supplements. (Any with dry-eye disease were excluded from the analysis.)

When the researchers comparedmortality among children who received the supplement with that of children in the control villages, they found "an astounding 70 percent reduction in mortality' attributable to the vitamin therapy, Sommer reports.

Two related studies offer clues as towhy the supplement affected mortality. One, published by Sommer and two colleagues in Tanzania in the Jan. 31 BRITISH MEDICAL JOURNAL, showed that among African children hospitalized with measles--a leading childhood killer in developing countries--the death rate can be halved by prescribing two high-dose vitamin A capsules in addition to standard medical care. Measles is known to deplete body reserves of vitamin A. This, the authors explain, "presumably reduc[es] the [body's] ability to resist secondary infections or their consequences, or both.'

Last year, researchers at the Universityof Adelaide and Adelaide Children's Hospital in Australia reported that smaller supplements--equivalent to eating an extra half-carrot daily--reduce by 20 percent the number of acute respiratory infections contracted by allergic or respiratory-illness-prone children. Since the Australian preschoolers ate diets that contained--even before supplementation--what should have been sufficient vitamin A, the study suggests that a history of acute infection may increase one's need for the vitamin.

Vitamin A therapy "is inexpensive'and "may very well have the potential to reduce child mortality on an astounding scale,' says Rep. Tony P. Hall (D-Ohio), who last week chaired a hearing of the House Select Committee on Hunger, where many of these findings were reported. Hall is heading efforts to increase U.S. funding for vitamin A supplementation in developing countries --from $6 million this year, to $8 million in the coming fiscal year.