What is the definition of vitamin A?
Vitamin A is a liposoluble vitamin, and we usually intake it as a provitamin that is converted into an active form by our body. After the provitamin form is converted into an active one it can perform some functions in our body. You have probably heard of beta-carotene, as it is the most known provitamin ofvitamin A, but actually, there are other provitamin forms too. It can be ingested as an active form too.
Vitamin A functions in the human body
- It helps in teeth formation and it helps to keep teeth healthy.
- It is included in the formation of the skeleton, mucosal membranes, skin, and soft tissues.
- It is also known as retinol because it produces the pigments in the retina of the eye.
- Vitamin A is very important for good vision, especially in low light. It may also be needed for reproduction and breastfeeding.
- It has antioxidative properties and protects our cells from free radical damage.
- Vitamin A is important for proper immune system response and for the regulation of the inflammatory responses.
Dry skin, night blindness, dry eyes, delayed growth, respiratory infections, poor wound healing, acne.
Symptoms of vitamin A toxicity
You cannot overdose yourself with vitamin A provitamins. Toxicity symptoms can occur only if you ingest toxic amounts of the active form of the vitamin A. Symptoms include:vision changes, dryskin, rough skin, swelling of the bones, mouth ulcers and confusion. If you overdose yourself with vitamin A during pregnancy, you are increasing the risk of birth defects.
How much vitamin A we need daily?
|Infants||0-6 months, 400mcg/day||7-12 months, 500mcg/day|
|Todlers||1-3 years, 300mcg/day||4-8 years, 400mcg/day||9-13 years, 600mcg/day|
|Adolescents and adults||Boys > 13 years, 900mcg/day||Girls >13years, 700mcg/day||
Food that is rich in vitamin A or vitamin A provitamins (the amount of vitamin A in the table is contained in 100gr of the product listed below)
|Sweet potato||4255 mcg|
|Beef liver*||9515 mcg|
*Be careful when consuming the active form of vitamin A, because as we have said beforeif you take too much vitamin A it can lead to toxic symptoms, however, this cannot happen if you consume the provitamin form found in plants.