Vitamins Guide – VITAMIN A

Vitamin A-Rich Foods

We will get to vitamin A-rich foods later on, but first, a bit of chemistry. Vitamin A is a fat-soluble organic substance stored in the liver. It is basically a cyclohexene ring with three connected methyl groups at the ortho and para positions, and an unsaturated hydrocarbon chain terminated by a hydroxyl functional group connected to the meta carbon atom on the ring. So Vitamin A is an alcohol, hence the –ol ending in the name retinol for the vitamin. Vitamin A is obtained as retinol (pre-formed vitamin A) found only in animal products and from yellow-orange plant pigments called carotenoids. Some carotenoids can be converted into vitamin A.

Carotenoids

There are over 600 carotenoids found in fruits and vegetables, but only a few are considered necessary for human health. Yellow, orange, red, and dark green fruits and vegetables are sources. Think of carrots, oranges, pumpkins, peaches, etc., and all leafy greens. Overcooking destroys carotenoids. The body converts them into vitamin A, e.g., the body converts 6 mcg of beta-carotene into 1 mcg of retinol vitamin A. Other pro-vitamin A carotenoids may take 8 mcg to yield 1 mcg of retinol.

Vitamin A RDA

The recommended daily allowance of vitamin A is 800 mcg for males and 700 mcg for females. The upper safe level is set at 1.5 mg.

Foods With Pre-formed Retinol

The list of vitamin A rich foods below are those high in preformed retinol or vitamin A. Preformed retinol is an active form of vitamin A. Once ingested, the body converts it into vitamin A.

Boiling or frying reduces a food’s vitamin A contentment by 40 percent after an hour and by 70 percent after a couple of hours, so be aware of that.

What Does Vitamin A Do?

Vitamin A from vitamin A-rich foods has several crucial functions in the body:

Derivatives of vitamin A are used to treat acne, psoriasis, wrinkles, and sunburn.

Retinyl acetate

One such derivative is retinyl acetate (retinyl retinoate, if you’re into the current terminology). This vitamin A derivative supports collagen synthesis 8 times more effective than vitamin A. It is also more effective for combating wrinkles and even works on mild to moderate acne by fighting bacteria and reducing sebum production. In other words, it’s good for fighting blackheads. Our EV-16 Vitamin Capsules [1] or Fizzy Vitamins [2] contain 0.8 mg of retinyl acetate.

Vitamin A and Eyesight

Vitamin A is converted into the important vision pigment in the retina called visual purple (rhodopsin). When exposed to visible electromagnetic radiation (light), visual purple stimulates the cone and rod cell nerve endings in the back of the eye (the retina). The effect is to trigger sensory messages that get relayed to the brain for interpretation by the visual cortex for images of what we see! You’re reading this web page because your vitamin A is working. This discovery was one of the first functions to be found of vitamin A – hence the name retinol.

Vitamin A and Immunity

Vitamin A obtained from vitamin A-rich foods also plays a significant role in strengthening your resistance and maintaining immunity. In addition, if you get an infection, this vitamin is needed in more substantial amounts because it is involved in the immune cell production required to line the mucus membranes of the respiratory and intestinal tracts. So, optimal vitamin A intake helps to protect against sore throats, coughs and sneezes, flu, warts, cold sores, and acute bronchitis.

Old Wives’ tales

There is no convincing evidence, however, that vitamin A supplementation protects against cancer. Several studies suggested that natural dietary intakes of the vitamin, plus some carotenoids, may reduce the risk of ovarian, stomach, prostate, and even colon cancers. But that’s as far as they go, and there has been no ratification. Actually, taking high doses of beta-carotene supplements has been linked with an increased risk of lung cancer in tobacco smokers.

Vitamin A Deficiency

Fortunately, Vitamin A deficiency due to a lack of eating vitamin A-rich foods is uncommon in developed countries, but unfortunately much more common in poorer parts. Sensitivity to green light is one of the first signs of the ailment. That is followed by night blindness – difficulty adapting to the dark. Carrots are so rich in vitamin A that one serving contains 184% of the RDA. That is why the adage “carrots help you see in the dark” is correct.

Severe Vitamin A Deficiency

More severe vitamin A deficiency causes dry, burning, itchy eyes. It can also lead to cornea hardening (the transparent part of the eye’s front) and even corneal ulceration. And inadequate levels of vitamin A from vitamin A-rich foods in the diet may lead to cataracts. Each year worldwide, maybe half a million people become blind from vitamin A deficiency.

Other Vitamin A Deficiency Symptoms

Don’t take these as proof of deficiency, but other symptoms are known to be scaly skin, flaky scalp, brittle hair, inflamed gums and mucus membranes, and loss of appetite. Anyway, deficiency is quickly rectified by eating vitamin A-rich foods.

Night Vision

The retinal tissue at the back of the eye is packed with light-sensitive cells called rods and cones. The cone cells are clustered around the fovea – a depression within the retina (the central part of the macula) where visual acuity is the highest and responsible for central vision. The rod cells, on the other hand, are only sensitive to dim light and hold good levels of the pigment called rhodopsin, with which vitamin A plays an essential role.

Rod Cells

For the low-light sensitive retinal rod cells to become responsive, the eyes must be kept away from bright light for at least 30 minutes, preferably 45 minutes. It is then that the rod cells start working. This time period to achieve this low-light sensitivity is called dark adaptation, and it virtually lets us see in the dark. The dark-adapted eye can see much more through a telescope, and even without one, the night sky is seen to be crowded with lots of faint stars the non-dark-adapted eye cannot see. The only downside to night vision is that we cannot see colors with it – all we see are shades of gray.

Dangers of sudden bright lights

Ask any astronomer whose eyes are dark-adapted what their biggest bugbear is. They’ll always respond with neighbors suddenly switching on lights, insecurity lights, and vehicle headlights. You see, as soon as the cone cells are activated, astronomers instantly lose their night vision and have to begin all over again. That’s why it’s a good idea for astronomers to work under a domed (see the above image) or roll-off roof observatory housing their fancy and precious telescopes. In order to read star charts, astronomers use red light, which doesn’t interfere with night vision! And it’s all thanks to vitamin A from vitamin A-rich foods.

Vitamin A Supplements

It is best to take vitamin A supplements with food, as dietary fat assists absorption of the vitamin. Nutritionists say it is most effective when taken with the antioxidants vitamins C, D, E, carotenoids, and the mineral selenium. As mentioned earlier, our EV-16 vitamin capsules containing all 16 essential minerals you’ll ever need contain 800 mcg of the more effective vitamin A derivative, retinyl acetate.

List of Vitamins in EV-16 Essential Vitamins and Fizzy Vitamins:

Overdosing with Vitamin A

Be careful of going over the top with vitamin A intake with supplements. That’s because it has a narrow therapeutic window. For example, doubling the RDA may cause problems during pregnancy, such as congenital disabilities. But dangerous toxicity occurs at doses above 30mg daily, but there’s no need to go into that here.

Polar Bear Liver

Fortunately, most people haven’t access to Polar Bear liver meat! Rumors say that eating the liver is extremely dangerous because it contains so much retinol that consuming just 100 g will kill you!

Five Vitamin A-Rich Foods to Help Boost Your Intake

Vitamin A is a crucial nutrient that plays a vital role in maintaining healthy vision, skin, and immune function. Fortunately, many delicious and nutritious foods are rich in vitamin A. Here are five vitamin A-rich foods you can easily incorporate into your diet:

Sweet Potatoes

Baked sweet potatoes are one of the delicious and nutritious vitamin A-rich foods. One medium-sized sweet potato contains 1.4 mg or a massive 560 percent of the daily recommended intake of vitamin A. They are also a good source of fiber, potassium, and vitamin C. Try roasting them in the oven with a sprinkle of cinnamon for a tasty and healthy side dish.

Carrots

Carrots are another of the definitive vitamin A-rich foods, with half a cup of raw carrots containing 459 mcg of vitamin A, or 57 percent of the RDA. They are also a good source of fiber and vitamin C. Try adding them to salads or stir-fries, or enjoy them as a crunchy snack with hummus or dip.

Spinach

Spinach is a nutrient-dense leafy green that is also one of the vitamin A-rich foods. Half-cup of boiled spinach provides 573 mcg of vitamin A, which is 71% of the RDA of vitamin A, as well as other essential nutrients like iron, calcium, and vitamin K. Add spinach to your salads or smoothies, or sauté it as a side dish for a boost of vitamin A and other essential nutrients.

Mangoes

Mangoes are not only a sweet and delicious fruit, but they are also one of the vitamin A-rich foods. 3/4 cup of mango provides 8 percent of the daily Vitamin A. Enjoy mangoes as a snack, add them to smoothies, or use them in salads for a tasty way to boost your vitamin A intake.

Red Bell Peppers

Finally, the last of the five vitamin A-rich foods are red bell peppers. These are not only a colorful addition to your meals, but they are also a great source of vitamin A. Half a cup of raw red pepper provides 117 mcg or 15 percent of the vitamin A RDA. Enjoy them raw in salads, roasted as a side dish, or sautéed in stir-fries for a delicious and nutritious boost to your diet.

Sources:

1. EV-16 Essential Vitamin Capsules

2. Simply Fizzy Vitamins

See also: vitamin B1; vitamin B2; vitamin B3; vitamin B5

Synonymous terms: vitamin a rich foods; foods rich with vitamin a

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