Which compounds are considered provitamin A and may reduce cancer risk?

Which compounds are considered provitamin A and may reduce cancer risk?

• A. Carotenoids
• B. Retinol
• C. Calciferol
• D. Tocopherol

Answer: (A)

Provitamin A compounds are substances the body can convert into active vitamin A. Carotenoids fit this role because some, like beta-carotene, can be turned into retinol in the lining of the intestine and in the liver. That conversion is why carotenoids are considered provitamin A. These compounds are plentiful in colorful fruits and vegetables—think carrots, sweet potatoes, spinach—and consuming them as part of a balanced diet has been linked to a lower risk of certain cancers. The protective effect is largely due to their antioxidant properties, which help guard cells from DNA damage, and their roles in supporting immune function and healthy cell growth. The other options aren’t provitamins: retinol is already active vitamin A, not a precursor; calciferol is vitamin D; tocopherol is vitamin E.

Provitamin A compounds are substances the body can convert into active vitamin A. Carotenoids fit this role because some, like beta-carotene, can be turned into retinol in the lining of the intestine and in the liver. That conversion is why carotenoids are considered provitamin A. These compounds are plentiful in colorful fruits and vegetables—think carrots, sweet potatoes, spinach—and consuming them as part of a balanced diet has been linked to a lower risk of certain cancers. The protective effect is largely due to their antioxidant properties, which help guard cells from DNA damage, and their roles in supporting immune function and healthy cell growth. The other options aren’t provitamins: retinol is already active vitamin A, not a precursor; calciferol is vitamin D; tocopherol is vitamin E.