Best food groups: Meat (especially liver), orange and green vegetables, fortified foods
Also consider: Beets, turnip and mustard greens, winter squash, dandelion roots (A 3½-ounce serving provides 14,000 IU, but don't eat any sprayed with weed killer!)
What is vitamin A and why is it so important? Vitamin A refers to a group of nutrients called retinoids that support healthy vision, skin, mucous membranes, bone growth, reproduction, and cell growth and maintenance. Vitamin A is stored mainly in the liver so, not surprisingly, the liver is a good source.
Did you know? Two forms of vitamin A are found in the diet: preformed, which comes from animal sources, and provitamin A (carotenoids), which comes from plant sources. Of the 563 identified carotenoids found mainly in orange, yellow, and red fruits and vegetables, fewer than 10 percent can be made into vitamin A in the body. Night blindness is one of the earliest symptoms of vitamin A deficiency. Long-term deficiency is a leading cause of preventable blindness in children. Vitamin A deficiency can also cause increased susceptibility to infections.
How much is enough?
The DV for vitamin A is 5,000 IU, based on a 2,000-calorie diet.
Excess vitamin A from animal sources can be toxic but not when it comes from plant sources, therefore there isn't a UL for beta-carotene or other provitamin A carotenoids. Beta-carotene can cause your skin to turn orange if consumed in excess. This is a harmless and reversible condition called carotenemia. Excessive retinol form of vitamin A (from animal sources), also known as hypervitaminosis A, can lead to birth defects, liver abnormalities, osteoporosis, and even death. In reality, the majority of hypervitaminosis A cases that occur are supplement, not diet, related.
Supplements: Beta-carotene, along with other carotenoids and the retinoid form of vitamin A, are available in capsule, tablet, and liquid form. Caution: High-dose vitamin A in supplement form has been linked to toxicity.
1. Liver
Here's how they rank:
1. Moose 3 ounces braised 81,600 IU
2. Turkey 3 ounces cooked 64,033 IU
3. Veal 3 ounces braised 59,979 IU
4. Goose 3 ounces cooked 34,218 IU
5. Beef 3 ounces fried 22,175 IU
6. Lamb 3 ounces braised 22,203 IU
7. Pork 3 ounces cooked 15,297 IU
8. Chicken 3 ounces fried 12,228 IU
Liver, such as calf 's liver, is one of the most nutrient-dense foods on earth. It is an excellent source of choline, copper, folate, iron, niacin, phosphorus, protein, vitamin B12, and zinc, and a good source of pantothenic acid and selenium. Because animal liver has a high concentration of the most absorbable form of vitamin A, retinol, it is not advisable to eat it every day, especially if pregnant. Liver is fairly low in fat, but unfortunately, it is high in cholesterol, so it is advisable to limit your intake to no more than a few times per week.
Did you know?
Did you know that 3 ounces of polar bear liver delivers nearly 3 million IU of vitamin A? This dose is so strong that it could kill you! Even in Eskimo culture, eating polar bear liver is forbidden!
2. Carrot Juice and Carrots
Carrot juice is an excellent source of alpha- and beta-carotene, and a good source of lutein and zeaxanthin, which are yellow pigments found concentrated in the retina of the eye. In fact, canned carrot juice contains four times more beta-carotene and five times more alpha-carotene than raw carrots. Cooking or juicing carrots helps break down their cell walls, which in turn increases the bioavailability (ability to absorb) of the carrots' beta-carotene from 5 to 90 percent! Also, a cup of carrot juice has nearly 700 milligrams of potassium, more than any other fruit or vegetable juice. Lutein and zeaxanthin, also found in unjuiced carrots, may help fight macular degeneration by blocking the absorption of blue light that causes damage to the photoreceptor cell layer.
3. Pumpkin
Pumpkin (and other deep yellow winter squashes) is an excellent source of fiber, vitamin A—specifically alpha- and beta-carotene, and a good source of antioxidants. Pumpkin also contains many other nutrients, including alkaloids; flavonoids; and linoleic, oleic, and palmitic acid, which may benefit in fighting diabetes and cancer due to their antioxidant and anti-inflammatory properties.
4. Sweet Potatoes
Sweet potatoes and yams look very similar, but botanically speaking, they are not even cousins. Because of the ongoing confusion among consumers, the USDA still requires that "yams" also be labeled as sweet potatoes. A large baked sweet potato is an excellent source of fiber and vitamins A, B6, and C. It is a good source of iron, magnesium, niacin, phosphorus, potassium, riboflavin, and thiamine. Sweet potatoes may benefit diabetics in two ways: A small study showed that including sweet potatoes in diets fed to type 2 diabetics had beneficial effects on glucose control and HbA1c (a marker of long-term glucose control), along with improved insulin sensitivity. Sweet potato was also shown to decrease fibrinogen, a substance that contributes to plaque in the arteries (so they are good for heart health, too!).
5. Spinach
Cooked and drained spinach is an excellent source of calcium, folate, iron, magnesium, riboflavin, and vitamins A, B6, C, E, and K. It is a good source of fiber, phosphorus, potassium, thiamine, and zinc. Spinach has been found to have a relaxing effect on arteries, reducing the risk of heart disease as well as lowering blood pressure.
6. Collard Greens
Collard greens are an excellent source of calcium, folate, manganese, and vitamins A and C. In addition, they are a good source of iron and fiber. When it comes to lowering cholesterol, cooked or steamed collards may be the way to go. One study showed that when collard greens were steamed, they possessed better bile acid–binding capacity, which helps trap cholesterol and remove it from the body, compared to raw collards.
7. Kale
Chopped, cooked kale is an excellent source of vitamins A, C, and K. It is a good source of calcium, fiber, iron, phosphorus, and vitamin B6. Kale is great juiced and terrific for your health! In fact, a study of men with high cholesterol levels who drank a little over ½ cup of kale juice everyday for 3 months saw their HDL ("good" cholesterol) and HDL to LDL ratios significantly increase by 27 and 52 percent, respectively. Their LDL ("bad" cholesterol) also was reduced.