How do carotenoids have vitamin A activity? ...

[soccerdreamer_17]

How do carotenoids have vitamin A activity?

Question 2

Cellular waste products must be readily excreted in order for the body to remain healthy. The waste products that accumulate can be actively excreted by all of the following organs except:
 
 A. the kidneys.
  B. the lungs.
  C. the skin.
  D. the hair.

[medine]

Answer to Question 1

Some carotenoid compounds can be converted to vitamin A.
Beta-carotene is a good example: When vitamin A is needed,
the human body can convert one molecule of beta-carotene
into two molecules of vitamin A (retinal). Supplementing the
diet may be appropriate when consumption of nutrients in
foods cannot meet a person's nutrient requirements. These
conditions might include:
 periods of rapid growth or when consequences of
normal aging make it difficult to consume adequate
amounts of food,
 following a weight-loss diet,
 a health condition that increases nutrient requirements,
 limited food access, and
 a vegan lifestyle.

Answer to Question 2

D

[soccerdreamer_17]

Wow, this really help

Gracias!