How Well Do
You Convert Beta-Carotene into Vitamin A?
By Marcia Wood
March 23, 2001
Beta-carotene adds attractive colors
and nutritional value to many familiar fruits and vegetables. Studies led by
Agricultural Research Service chemist
Betty J. Burri during the past five years provide new information on the
ability of our bodies to absorb beta-carotene and convert it into an essential
nutrient, vitamin A.
Burri's findings are important for people who are cutting back on the amount
of meat or dairy products--foods that are rich in vitamin A--that they eat.
Those individuals need to be sure they are getting an adequate supply of
vitamin A from other sources, Burri pointed out. She is with the ARS
Western Human Nutrition Research
Center in Davis, Calif.
Vitamin A is essential for proper growth and reproduction, as well as for
Burri found new extremes in the amount of time it takes for beta-carotene to
be absorbed and converted, and in the amount that is converted. Among the most
unexpected results was a statistically significant difference in beta-carotene
uptake and conversion by physically similar volunteers.
About half of Burri's 45 volunteers--male and female--didn't take up much
beta-carotene at all. And about half of the volunteers didn't form much vitamin
A from the beta-carotene they did absorb.
Variation in the way our bodies respond to beta-carotene is likely
gene-based, according to Burri. Nutrition scientists might soon be able to use
new information coming from human genome researchers to develop customized
dietary guidelines that take into account an individual's ability to convert
beta-carotene into vitamin A.
The current issue of the ARS monthly journal, Agricultural Research, tells more.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.
Scientific contact: Betty J. Burri, ARS Western Human Nutrition
Research Center, Davis, Calif; phone (530) 752-4748, fax (530) firstname.lastname@example.org.