Vitamin A

What is it? 

Vitamin A is a vitamin which is found in food like eggs, vegetables, fruits, butter, fortified margarine, whole milk, meat and saltwater fish. It is required by our body for the development and healthy function of our immune system, sight , skin and other parts of the body.  

Benefits

There are ongoing research conducted to prove that it is effective for patient with vitamin A deficiency, reduce risk of breast cancer, reduce risk of cataracts, reduce risk of measles complications, decrease malaria symptoms, improves healing after eye lasik surgery and slows progression of retinitis pigmentosa.

More randomized controlled research studies need to be conducted to prove other proclaimed benefits.

Possible side effects 

At normal dosing it is likely safe for most people including children.

However taking higher doses than recommended will cause side effects such as fatigue, irritability,stomach discomfort, nausea, vomiting, mental changes, anorexia, mild fever and excessive sweating.  

Pregnant and lactating woman can take vitamin A but not more than the recommended dosage as too high doses can cause birth defects.

Alcohol will increase vitamin A toxic effects on the liver hence they should not be consumed together.

People with liver disease should avoid vitamin A supplements as it may worsen liver toxicity.

Drug-Drug Interactions

Retinoids contain vitamin A , if taken together with vitamin A supplements the side efefcts will be doubled.

Tetracycline (antibiotics) should not be taken with vitamin A as it increases the risk of intracranial hypertension.

Hepatotoxic drugs and vitamin A when taken together will increase the risk of liver damage.

Warfain : taking vitamin a with warfarin will increase the risk of bruise and bleeding.

Dosage
The recommended dietary allowance (RDA) for Vitamin A which comes from food and supplements are: 

CHILDREN

1-3 years : 300 mcg/day (or 1,000 International Units/day)

4-8 years: 400 mcg/day (1,320 IU/day)

9-13 years: 600 mcg/day (2,000 IU/day)

FEMALES

14 years and up: 700 mcg/day (2,310 IU/day)

Pregnant

14-18 years: 750 mcg/day (2,500 IU/day)

19 years and over: 770 mcg/day (2,565 IU/day)

Breastfeeding

Under 19 years: 1,200 mcg/day (4,000 IU/day)

19 years and over: 1,300 mcg/day (4,300 IU/day)

MALES

14 years and up: 900 mcg/day (3,000 IU/day)