Pioneers of Discovery
· · · · · · · · · · · ·
The "Magic Bullet"
Keeps on Delivering
By Lavinia Edmunds
From Indonesia to South India, from Nepal to Ghana, life-saving findings involving vitamin A keep coming in from Hopkins School of Public Health researchers. All are new variations on a theme sounded loud and clear by Hopkins ophthalmologist Alfred Sommer in 1982.
Hoping to learn more about the high incidence of eye disease among children in rural Indonesia, Sommer and colleagues conducted a major epidemiological survey of preschool-aged children in the villages of Indonesia. These eye ailments (in particular night blindness and dry eyes) were known to be a result of vitamin A deficiency. When sifting through reams of numbers back home in Baltimore, he was astounded by what he found.
"Holy cow!" Sommer recalls exclaiming, as he sits in his office at Public Health, where he has served as dean since 1990. Children with eye problems due to vitamin A deficiency were dying at a much higher rate than those without eye problems-- four to eight times more frequently, a follow-up study conducted by Sommer and his colleagues would show. Further, children treated periodically with small yellow capsules of vitamin A experienced reduced mortality of 30 percent.
Sommer's findings were not universally embraced. Some mistrusted Sommer for his obvious enthusiasm, even passion, for the vitamin A cause. Others thought limited resources should be directed toward malnutrition and AIDS--problems they deemed more pressing.
But later studies, conducted by Hopkins researchers and others in India, the Philippines, and Nepal, soon proved to the world the healing powers of the vitamin. "What astounded me personally, except for one poorly designed study in India, was that all the studies came within the same range of reduction," Sommer says. "For children between 1 and 6 years, there was between 33 and 55 percent reduction in mortality. That locked it in solid."
Equipped with these findings in 1992, Sommer organized and chaired a conference of some 25 researchers from around the world at the Rockefeller Study Center in Bellagio, Italy. Their conclusions became known as the Bellagio Brief. "That became the flag to wave...because there were policy implications," says Sommer. An economic analysis done by the World Bank showed that vitamin A capsules, at a mere 2 to 3 cents per dose, were one of the most cost-effective health interventions in the Third World.
Today, notes Sommer, "over 70 countries have vitamin A control programs." In Indonesia, vitamin A deficiency is virtually unknown.
For his discovery that vitamin A deficiency causes death from infectious diseases in millions of children, and for showing vitamin A's efficiency in averting such consequences, Sommer won the coveted Albert Lasker Clinical Medical Research Award in 1997.
Sommer is quick to acknowledge his debt to Elmer McCollum, who joined the Public Health faculty in 1918. Before coming to Hopkins, McCollum had done tests with albino rats. He found that when they were fed a diet in which lard, olive oil, or almond oil provided the sole sources of fat, they could not grow or remain in good health. The rats lost vision and hair, and even died in extreme cases. Rats given butter, cod liver oil, or egg yolk remained healthy. McCollum called the essential ingredient fat-soluble vitamin A.
McCollum mounted the first public education campaign promoting nutrition--vitamin A, in particular. He wrote columns for McCalls magazine, testified before Congress, and made countless speeches extolling the virtues of vitamins and fortification. Today, thanks to the fortification of milk and other foods, there are only a few isolated cases of vitamin A deficiency in the United States.
"McCollum combined science with proselytizing. He was unique in recognizing and dedicating himself to the practical application of his discoveries," says Sommer.
Currently, Public Health researchers are continuing to write important new chapters of the vitamin A story, this time focusing on maternal health. They have established a base of operations in the southern plains of Nepal, where night blindness is so common in the third trimester of pregnancy that it is considered as inevitable as morning sickness.
Hopkins researchers set up a controlled field trial to track 44,646 married women of child-bearing age; about half became pregnant during the more-than- three-year study. All the women were divided into three groups and given, respectively, a placebo, vitamin A capsules, and carotene (which is converted to fat-soluble vitamin A in the liver). The pregnant women who received vitamin A or carotene had lowered mortality by 40 percent. And vitamin A reduced night blindness by a whopping 70 percent.
"It's just the tip of the iceberg," says Keith West (pictured at right), principal investigator for the study. With the fetus depleting vitamin reserves, a high proportion of pregnant women suffer from anemia and infections, as well as night blindness. A follow-up showed that the risk of morbidity and mortality continues beyond 12 weeks (the conventional postpartum period), to two years.
In Bangladesh, West and a team of five other researchers are setting up a similar study of pregnant women that would shore up the Nepal findings and possibly pave the way for a plan to distribute vitamin A capsules to pregnant women throughout Third World countries.
Additional work is examining vitamin A's interaction with other vitamins and minerals such as zinc. "The next vitamin A story," Sommer predicts, "may be the zinc story, in that we find children in developing countries are zinc-deficient, the deficiency is widespread, and it seems to be related to infectious diseases. We could be on the cusp of that discovery."
RETURN TO APRIL 2000 TABLE OF CONTENTS.