Here is the second installment from V. Great stuff.
Let’s Talk Nutrition: Vitamin A (and a little Beta-Carotene)
Vitamin A is one of the most important vitamins to our bodies. Also called Vitamin A Retinal and retinol, this vitamin functions in a multitude of ways within the body. Both forms of the vitamin are necessary, and come from different sources.
Retinal, the type found in plants (in the form of beta-carotene) is used by the retina of the for both low-light and color vision. The yellow and orange pigments in foods is caused by the beta-carotene content. The body processes that into Vitamin A during digestion. Retinol is the other type of Vitamin A we need and can be found in foods of animal origin (meat, milk, etc). It contributes to the formation and health of epithelial and other cells.
In certain parts of the world where a deficiency in Vitamin A is rampant, many children go partially or completely blind at a very young age.
Chronic deficiencies in Vitamin A can lead to:
- Night blindness and other eye problems
- Reduced resistance to infection
- Impaired growth
- Weight loss and anorexia
- Improper tooth and bone formation and crooked teeth.
Vitamin A is one of the vitamins which can be synthesized, though as with most nutrients, the synthesized version isn’t preferable. However, for vegetarians and cultures with little to no foods of animal origin in their diet, this can be an incredibly important supplement to have access to. There are tons of Vitamin A-fortified foods on the market that fit into almost every dietary niche.
As opposed to potassium, which is water-soluble, “A” is fat-soluble. It is very important to understand the differences between fat- and water-soluble vitamins. You’ll recall from the previous article that with water-soluble vitamins the body simply eliminates what it can’t use immediately. Fat-soluble vitamins on the other hand (as the name implies) are stored in the fat of the body.
Because of this, it is possible (and dangerous) to ingest too much of certain vitamins, including A. The adage “Too much of a good thing…” definitely applies. Building this particular vitamin to toxic levels happens over a long period of time. You would have to be ingesting upwards of 25,000mgc every day for a period of months in order to raise it to toxic levels, so don’t shy away! Just be aware of how much you are taking in from all of the different sources.
Symptoms of having too much Vitamin A in the body are nausea, irritability, blurry vision, and loss of appetite. Chronic deficiencies can lead to hair loss, fatigue, and persistent insomnia.
So, how much do you really need?
Well, as with most vitamins “That all depends…” If you’re already a fairly healthy individual, then somewhere in the 800mcg range is probably sufficient. If you are trying to become pregnant, are pregnant or nursing, then you should aim higher; somewhere around the 2000-3000 mark. Your baby ingests everything you do, and Vitamin A is so important in the pre-natal stages and fetal development.
Where do we find this eye-catching vitamin? So glad you asked 😉
Food of animal origin: pork, sausage, steak, chicken, organ meats, eggs, milk, cheese, fish
Food of plant origin (in the form of beta-carotene): carrots, sweet potatoes and yams, broccoli, dark leafy greens, apricots. Most intensely colored fruits and vegetables will contain beta-carotene.
There is a very thorough, comprehensive list of Vitamin A/Beta-Carotene content in foods in pdf format here:
Vitamin A is the fifth one down on the list. Content and daily values are in micrograms (mcg).