Vitamin A History:
Did you know that vitamin A was the first vitamin discovered?
There are all these vitamins we know of now, but if you actually thought about it, the first letter in the alphabet makes sense to name that very first vitamin discovered.
In the early 1900s researchers first recognized that a certain substance in animal fats and fish oils was necessary for the growth of young animals.
That substance was eventually named vitamin A.
Vitamin A Benefits :
Vitamin A’s most clearly defined role is one that it plays in vision.
Metabolites of the vitamin combine with certain proteins to make visual pigments that help the eye adjust from bright to dim light.
That process uses up a lot of vitamin A and if not replaced can cause night blindness.
Vitamin A is also important for normal growth and reproduction – especially proper development of bones and teeth.
Studies show that vitamin A is essential for normal sperm formation, for growth of a healthy fetus, and for the synthesis of steroid hormones.
Vitamin A also is important for preserving healthy skin – inside and out!
Taking extra vitamin A won’t make your sagging skin suddenly beautiful, but a deficiency will cause skin problems.
Vegetables High in Vitamin A:
Carotenoids, found in plants, are a group of pigmented compounds, including provitamins, that the body can convert to vitamin A.
Bright orange beta-carotene is the most important carotenoid because it yields more vitamin A than alpha- or gamma-carotenes.
Foods like orange and yellow fruits and vegetables have high vitamin A activity because of the carotenoids they contain.
Generally, the deeper the color of the fruit or vegetable, the higher the concentration of carotenoids it has.
Carrots are especially good sources of beta-carotene and therefore high in vitamin A value.
Green vegetables, such as spinach, asparagus, and broccoli, also contain large amounts of carotenoids, but their intense green pigment, courtesy of chlorophyll, masks the tell-tale orange-yellow color.
How To Meet Your Vitamin A Requirements:
The recommended dietary allowance for vitamin A is 800 retinol equivalents for women and 1,000 retinol equivalents for men.
Retinol equivalents are the preferred measure for vitamin A because this method takes into account both forms of the vitamin – retinol and carotenoids.
One retinol equivalent is equal to 3.33 international units (IU) or 10 IU of beta-carotene.
Assuming you get the vitamin from both sources, the recommended dietary allowance is equivalent to about 4,000 IU for women and 5,000 IU for men.
However, it is not necessary to obtain the recommended dietary allowance each day.
As vitamin A is not soluble in water, you do not excrete excess amounts of the vitamin.
Your liver stores vitamin A and the body can tap into the reserves whenever dietary intake is too low.
For most adults it takes months to deplete stored amounts.
As long as you are eating plenty of yellow and green vegetables, your overall intake should be sufficient to provide the vitamin A your body needs.
Recommended Dietary Allowances (RDAs) for Vitamin A :
Foods High in Vitamin A :
(Foods high in vitamin A listed in order of most bang for the buck, so to speak):
|Food||Quantity||International Units (IU)|
|Sweet potatoes, baked (peeled after baking)||1 medium||28,805|
|Pumpkin, canned||1/2 cup||27,018|
|Sweet potatoes, candied||1 medium||25,188|
|Spinach, canned, drained||1 cup||18,781|
|Sweet potatoes, canned||1 cup||15,966|
|Spinach, cooked, fresh or frozen||1 cup||14,790|
|Carrot, raw||1 medium||12,767|
|Peas and carrots, frozen (boiled, drained)||1 cup||12,418|
|Apricot halves, dried||1 cup||9,412|
|Turnip greens, cooked||1 cup||7,917|
|Apricots, dried, cooked, unsweetened||1 cup||5,908|
|Vegetarian soups, ready to serve||1 cup||5,878|
|Cabbage, spoon or bok choy, cooked||1 cup||4,366|
|Collards, cooked||1 cup||3,491|
|Broccoli, cooked, drained||1 cup||3,481|
|Apricots, canned in heavy syrup||1 cup||3,173|
|Red pepper, cooked||½ cup||2,577|
|Watermelon, raw||1 wedge||1,764|
|Tomatoes, canned (solid and liquid)||1 cup||1,450|
|Apricots, raw||3 medium||1,110|
|Tomatoes, raw||1 medium||841|
|Lettuce, cos or romaine||1 cup||780|
|Tomato juice, canned||½ cup||674|
|Plums, canned with syrup||1 cup||668|
|Prunes, dried, medium||1 cup||649|
|Peach halves, dried, cooked, unsweetened||1 cup||508|
|Peaches, raw||1 medium||465|
|Endive, curly||½ cup||297|
|Corn, fresh or frozen||½ cup||203|
|Orange juice, unsweetened, fresh or frozen||½ cup||194|