Types of Vitamin A
There are 2 types of Vitamin A in the human diet:
- Preformed vitamin A (also called retinol) is used directly by the body and is found in animal products like eggs, milk, and liver.
- Provitamin A carotenoids are found in green leafy vegetables, orange/yellow-coloured fruit and vegetables like cabbage, carrot, lettuce, spinach, mango. By far the most important provitamin A carotenoid is beta-carotene (1)
What does Vitamin A do for you?
Vitamin A help preserve vision, fight infections, maintain healthy skin and bones, and regulate cell growth and division. Without enough vitamin A, you may be at a higher risk for night blindness or experience skin disorders or infections. It is also a key structural component in the development and maintenance of the heart, lungs, kidneys and other organs.
Vitamin A plays a critical role in:
- Maintaining body homeostasis
- Prevention of anemia
- Support pregnancy metabolism
- Pregnancy fetal development, especially bones, teeth, skin, and vision
So do you need to have good source of Vitamin A during pregnancy? The truth is developing babies need some Vitamin A. Vitamin A deficiency can lead to fetal and infant growth retardation. In fact, The World Health Organization (WHO) estimates that between 250,000 and 500,000 children are born blind every year. WHO also estimates that 13.8 million children have some degree of visual loss related to vitamin A deficiency.(2) If the pregnant mother don’t have enough Vitamin A in her body to start with, how would the fetal development be normal?
It is important to remember however that taking too much Vitamin A during pregnancy brings a small risk of birth defects, however too little Vitamin A brings risk of visual loss and growth retardation hence it will be extremely important to take a balance.
The Linus Pauling Institute states that “No increase in the risk of vitamin A-associated birth defects has been observed at doses of preformed vitamin A from supplements below 3,000 mcg/day (10,000 IU/day). Since a number of foods in the U.S. are fortified with preformed vitamin A, pregnant women should avoid multivitamin or prenatal supplements that contain more than 1,500 mcg (5,000 IU) of vitamin A. Vitamin A from beta-carotene is not known to increase the risk of birth defects.”
How much Vitamin A you need:
(RDAs for vitamin A are given as mcg of retinol activity equivalents (RAE) to account for the different bioactivities of retinol and provitamin A carotenoids)
Pregnant women age 18 and younger: 750 mcg RAE per day
Pregnant women age 19 and older: 770 micrograms RAE per day
Breastfeeding women age 18 and younger: 1,200 mcg RAE per day
Breastfeeding women age 19 and older: 1,300 mcg RAE per day
Nonpregnant women: 700 mcg RAE per day
You don't have to get the recommended amount of vitamin A every day. Instead, aim for that amount as an average over the course of a few days or a week.
2. Vision Disorders—Advances in Research and Treatment: 2012 Edition
Dr Nicole Ng (MBBS) is a medical doctor with a passion in women's health and medical research