Vitamins and minerals

For the next few months, we will discuss one vitamin and one mineral in each blog entry. This will continue until we have covered all the vitamins and minerals. This entry is for vitamin A and iron.

Vitamin A

Vitamin A is a fat-soluble vitamin that helps promote healthy vision, growth of cells in the body, and protects from infections.

Carotenoids (such as beta-carotene) will form vitamin A in the body so they are grouped similarly to vitamin A. Carotenoids work as antioxidants, which help prevent damage to cells in the body. Antioxidants help improve immunity and lower risk for certain diseases, infections, and cancer.

Vitamin A comes from animal sources such as liver, fish oil, eggs, and milk. Other foods may be have vitamin A added to them.

Carotenoids, which form vitamin A, come from plant foods that are red, yellow, orange, and dark leafy greens. We've always associated carrots with our eyes, which is true because the orange color of carrots is beta-carotene and helps us with healthy vision.

Vitamin A is listed on the food label and the %Daily Value is based on 5,000 IU daily. Men need about 3,000 IU daily and women need about 2,333 IU daily. IU means International Unit and that is one way that some vitamins are measured.

Vitamin A supplements do not usually need to be taken. Vitamin A can be stored in the body and excessive amounts can be toxic. Vitamin A needs can be met easily by foods that we eat.

To see what foods contain vitamin A and how much they contain, click on this link. Scroll about halfway down the page and make sure you look in the category for vitamin A, IU because vitamin A is measured in a few different ways.


Iron

Iron is a mineral that is part of hemoglobin, which carries oxygen in your blood to the parts of your body where it needs to go. Iron also helps in brain development and supports a healthy immune system.

Iron comes from both plant and animal foods. Heme iron (from animal sources) is better absorbed by the body than from non-heme (plant) sources. If you combine your non-heme sources of iron with vitamin C or with heme iron sources, it helps with absorption. Certain foods and drinks, such as spinach, chocolate, tea, and coffee inhibit iron absorption as well, so add vitamin C foods and heme sources of iron to overcome those "inhibitors."

Adults males and all adults over the age of 51 need 8 mg daily, whereas adult women between the ages of 19 and 50 need 18 mg daily.

To see what foods contain iron, click here.

Your body adapts to iron needs, absorbing more when stores and low and absorbing less when stores are higher. Iron needs are highest during rapid growth.

(Information source: ADA Complete Food and Nutrition Guide, 3rd edition. Weblinks are from the Linus Pauling Institute, Oregon State University)