In nutrition, bioavailability means that nutrients are best absorbed from food sources rather than supplementation. This is why I am so convinced that a diet rich in variety is the best way to be as healthy as possible.
Of course, this is an oversimplification. There are always exceptions as there are often factors that prevent people from absorbing this nutrition or even being able to ingest it, such as celiac and other malabsorption disorders. For the most part, however, try to get your nutrition from food.
My husband and I were at a pharmacy not too long ago and he asked me if I wanted to pick up any supplements besides our Vitamin C and Vitamin D. As a general rule I’m against supplementation- our diet is rich enough and varied enough, in my opinion, to cover most of our nutritional bases. When the pharmacist heard me she piped up from behind the counter, “Yes, exactly!”
Today I’m spotlighting Vitamin A. On my Facebook page this week our general food theme is cherry tomatoes. We talked about their history, benefits, and what happens when you eat too many of them on Monday, and on Friday we’re going to do a recipe roundup that features cherry tomatoes. If you haven’t already “liked” and “followed” my Facebook page, I encourage you to do it today so that you don’t miss out!
Vitamin A is responsible for eye health, bone health, reproductive health, and cell division. It helps to regulate immune system function and more is needed when infections are present. It may also play a role in fighting cancer.
You can get Vitamin A from both animal and vegetable sources in the form of beta carotene. This is the precursor to Vitamin A- and this is what’s found in tomatoes. 1 cup of cherry tomatoes contains 1241 iU (international units) of Vitamin A. Not a small amount!
It's much harder to overdose on food sources of vitamins and minerals than it is on supplements. Too much of a good thing is still too much. You can overdose on Vitamin A supplements easily as it’s stored in the liver and not sent out of the body when not needed- it’s a fat-soluble vitamin rather than water soluble, such as vitamin C. Overdosing is a gradual event, and long term liver damage is not reversible.
Adults need between 2310 and 4300 iU of Vitamin A daily, depending on their age, sex, and whether or not they are pregnant or nursing. Children need between 1000 and 2000 iU per day, again depending on age and sex. Here is my source for this information.
To summarize, Vitamin A is important to:
-Support your immune system, eye health, bone health, reproductive health, and supports the body in fighting cancer.
You can find Vitamin A in these food sources:
-Eggs, liver, fatty fish (such as salmon and steelhead trout) and beta carotene (which the body converts) from tomatoes, dark leafy greens (such as kale), mangoes, carrots, and so on.