Quick article about vit A
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Pete Ryan www.veganbodybuilding.org
Vegan diets are best for vitamin A
May 1, 10:02 AM
An article in this month’s Clinical Nutrition Insight suggests that
Americans may be getting too much vitamin A in their diets—and that it
is best to get this nutrient from plant sources.
Preformed vitamin A, which is called retinol, is found only in animal
foods. However, plant foods contain carotenoids which are converted in
the body to vitamin A. The best known and most abundant vitamin A
precursor is beta-carotene.
While preformed vitamin A from animal foods is toxic at high intakes,
carotenoids are not. And too much preformed vitamin A—even at levels
that aren’t toxic—has been linked to risk for bone fracture in some
studies. High vitamin A intake might be especially harmful for people
who have low intakes of vitamin D and for those who use retinol-rich
supplemental products like cod liver oil.
In a recent editorial on the subject, Dr John Cannell noted that “The
body uses these carotenoid substrates to make exactly the right amount
of retinol. It is a closed, tightly regulated system, one designed to
perfection by Nature.” He suggested that consuming animal-derived
vitamin A bypasses the controls of this delicate balance.
Carotenoids, which are found in a wide variety of fruits and
vegetables, have other health benefits in addition to their vitamin A
activity. They have been linked to decreased cancer and heart disease
risk and may protect vision in aging. It’s no surprise that
vegetarians tend to have higher blood levels of carotenoids compared
to people who eat meat. But, to get adequate vitamin A, everyone
should consume one or two servings of beta-carotene superstars every
day. These are sweet potatoes, carrots, spinach, kale, collards,
cantaloupe, and dark yellow winter squash (like Hubbard and
Butternut). Carotenoids need a little dietary fat for absorption and
are better absorbed from foods that are lightly cooked.