Vitamin A
Vitamin A is a powerful antioxidant and is responsible for the maintenance of healthy cells, vision and your immune system.
Sweet potato and other brightly pigmented fruits and vegetables are a great source of Beta-Carotene (which is a precursor of Vitamin A).
Beta-Carotene as the precursor simply means that it is then transformed into Vitamin A in the body for use. This is determined and regulated by Vitamin A status in the body.
In all plant foods, Beta-carotene is the present compound and preformed Vitamin A is only found in animal products (as it’s transformed in the animal’s body from consumption of plant foods).
However, a preformed compound does not necessarily mean it is better.
An upper limit for Vitamin A is set in place but there is no set upper limit for Beta-Carotene.
An upper limit is set for some nutrients to determine a safe level of consumption, anything consumed above the designated safe level can induce toxicity and in turn bring about adverse side affects.
Although Beta-Carotene is a precursor for Vitamin A, there is not upper limit as it’s conversation rate is determined by Vitamin A levels in the body, therefore, if it is not needed it will not be converted into Vitamin A.
Symptoms of a toxicity can include liver damage and bone malformations.
Symptoms of a deficiency can include dry skin, headache, irritability, vomiting, bone pain, night blindness, increased risk of infection.
Good food sources include dark green and brightly pigmented (red, orange, yellow) fruit and vegetables such as:
Carrots
Sweet potato
Spinach
Apricots
Cantalopoue
Tomatoes