Description

Test Criteria

Vitamin A comes from two sources. One group, called retinoids, comes from animal sources and includes retinol. The other group, called carotenoids, comes from plants and includes beta-carotene. The body converts beta-carotene to vitamin A. Major carotenoids, including lycopene, lutein, and zeaxantuin, have important biological properties, including antioxidant and photoprotective activities.

It is rare in the developed world to have a serious deficiency of vitamin A. Symptoms include:

• Dry eyes
• Night blindness
• Diarrhea
• Skin problems