Vitamins from A to …

We all know or at least heard that vitamins are important as part of your regular diet.  But what is a vitamin and how does it contribute to your overall health and wellness?  In addition, how does each one function and which ones should I pay particular attention to?

Wikipedia defines a vitamin as follows:

A vitamin is an organic compound and a vital nutrient that an organism requires in limited amounts.  An organic chemical compound (or related set of compounds) is called a vitamin when the organism cannot synthesize the compound in sufficient quantities, and it must be obtained through the diet; thus, the term “vitamin” is conditional upon the circumstances and the particular organism.

In the next series of posts, I will briefly describe each vitamin, how it functions in your body, what foods provide them, what quantities should one consume, side effects, and whether they are soluble or insoluble (more on that soon).

So without further ado, here we go starting with…

Vitamin A…

This vitamin is known for its benefits towards vision and the immune system.  To make things a little confusing, there are two types on vitamin A, one that comes from animal sources known as retinoid and the other from plant sources known as beta-carotene.

The vitamin A you get in supplements are from the plant source, beta-carotene.  The recommended minimum requirement is 10,ooo IU per day.  An IU is defined as a quantity of a biologic (such as a vitamin) that produces a particular biological effect agreed upon as an international standard.

Most nutritionists will tell you that you can get 65% of the recommended daily amount of vitamin A by having five servings of fruits and vegetables a day but the reality is, how many people have the capability of doing that?

Food sources…

Vitamin A plant sources come from sweet potato, carrots, spinach, kale, mustard greens, collard greens, turnip greens, beet greens and squash in that order.

Vitamin A animal sources come from eggs, whole milk, fish (in particular tuna), liver, and fortified skim milk.

Retinoid or Carotene?

Although some vegans would debate this, the most efficient way of getting your vitamin A is from animal sources not plant sources.  This is because no matter what source you get it from, it must be converted to retinoid to be fully effective.

This means plant source vitamin A has to go through a process.  The downside to that is that it takes six units of carotene to produce one unit of retinoid.  Highly inefficient!

Fat soluble or Water soluble?

Vitamins are either fat or water soluble.  From it is identified as such:

Vitamins are classified as either fat soluble (vitamins A, D, E and K) or water soluble (vitamins B and C). This difference between the two groups is very important. It determines how each vitamin acts within the body.

The fat soluble vitamins are soluble in lipids (fats). These vitamins are usually absorbed in fat globules (called chylomicrons) that travel through the lymphatic system of the small intestines and into the general blood circulation within the body. These fat soluble vitamins, especially vitamins A and E, are then stored in body tissues.

Fat soluble vitamins, once they have been stored in tissues in the body, tend to remain there. This means that if a person takes in too much of a fat soluble vitamin, over time they can have too much of that vitamin present in their body, a potentially dangerous condition called hypervitaminosis (literally, too much vitamin in the body).

Persons can be also be deficient in the fat soluble vitamins if their fat intake is too low or if their fat absorption is compromised, for example, by certain drugs (that interfere with the absorption of fat from the intestine) or by certain diseases such as cystic fibrosis (in which there is a deficiency of enzymes from the pancreas which similarly interferes with the absorption of fat from the intestine).

What this amounts to is this.  Fat soluble vitamins being that they ae stored in your body’s fat, are not urinated away like in water soluble vitamins.  This means that if you take too much of fat stored vitamins, you may start hitting toxic levels.  As noted above, vitamin A is fat stored.

Side Effects…

Is there such a thing as too much vitamin A?  While rare, Yes…

Some common symptoms of too much vitamin A include:

blurred vision, headaches, drowsiness, decreased appetite, bone pain, nausea, skin and hair changes, sensitivity to sunlight just to name a few.

This concludes the first in a series of vitamins.  Stay tuned as we hit the B’s, a very complex series of vitamins for the body in order to stay…. Fit Forlife!






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