Vitamin A is the name given to a group of fat soluble substances you get from eating plants, animal products and regular vitamin supplements. They are important for your vision, immune system, bones and internal organs. Lack of vitamin A during your pregnancy and nursing many cause blindness and susceptibility to infections in your infant.
It is important to realize that there are two types of Vitamin A. The first type of Vitamin A comes from animal products (as well as milk) and are called ‘preformed’ meaning that they are already biologically active. Retinoic acid, Retinal and Retinol (all starting with the letter “R”) are the common types of vitamin A found in animal products. We find high levels of them in the liver and lower amounts in fish, eggs and milk. Very little is found in regular meats.
An intake of over 10 000 Units per day of these preformed types of vitamin A, especially during the first trimester, may cause fetal malformations of the face and skull as well as with the nervous system and heart. Since liver has very high levels of preformed Vitamin A, many medical providers recommend limiting its intake while pregnant and to verify that your vitamin supplements do not contain these type of Vitamin A.
The second type of Vitamin A comes from plant sources and are nearly impossible to overdose on. They are “provitamins”, meaning they are minimally active themselves and are completely safe. They consist of the Carotenes and Cryptoxanthines (both starting with the letter “C”), which are converted to the active form of vitamin A only when your body needs it, making it very hard to overdose on them. We find high concentrations of them in yellow and green vegetables such as carrots, sweet potatoes, and spinach.
Vitamin A contents in foods (single portion)
Animal source (preformed):
- 3 oz beef liver – 22,000 units
- Milk – 500 units
- Butter (1tbsp) – 350 units
- Egg – 250 units
- Low fat yogurt – 100 units
- 3 oz can tuna – 65 units
- Salmon – 175 units
- Chicken breast & skin – 40 units
- Steak – minimal
Plant source (safe since Provitamin):
Sweet potato – 28,000 units
- Spinach – 11,000 units
- Carrot – 9,000 units
The amount you need to take daily:
- Non pregnant woman – 2330 units per day
- Pregnant 2560 – units per day
- Breastfeeding woman – 4330 units per day
In summary, vitamin A is important for fetal development but you can get too much if you eat liver or if your vitamin supplements contain preformed vitamin A such as Retinal and Retinol.