Vegan diets are best for vitamin A

[Guest guest]

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.

 

 

 

 

Author: Virginia Messina, MPH, RD

Virginia Messina, MPH, RD is an Examiner from Seattle. You can see Virginia's

articles on Virginia's Home Page.