Nutrition lecture: Vitamin A

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Vitamin A (Retinol)

Vitamin A comes as a group of fat-soluble retinoids, including retinol, retinal, and retinyl esters. Vitamin A is involved in immune function, vision (see in the night-rhodopsin), maturation/development, reproduction, and cellular communication (skin, mucous). We can get vitamin A from Plants (B-carotene) and animals (Liver, Dairy products, Fish, Kidneys).

Excess of vitamin A is stored in our liver so daily intake is not necessary needed but you should aim to get enough over the week.

Forms of Vitamin A

Vitamin A can exist in three forms:

  • Retinol (from animal products)- also know as vitamin A1, can reduce fine lines and wrinkles by increasing the production of collagen, stimulate the production of new blood vessels in the skin, which enhance skin color. Additional benefits include fading age spots and softening rough patches of skin. As a supplement it is used to treat and prevent vitamin A deficiency, especially that which results in xerophthalmia ( can result blindness).
  • Retinal (plant products)- also known as retinaldehyde, allows certain microorganisms to convert light into metabolic energy. It been proven that retinal work 11x faster than retinol also have a higher exfoliation rate than retinol which contribute to a radiant skin.
  • Retinoic acid- is a metabolite of vitamin A1 which intervene and mediate the required functions for cell growth and development. Retinoic acid is use in medicine to treat some skin diseases and play a really important role in a healthy skin.

Retinol can transform in retinal and retinoic acid. Retinal can transform in retinol and retinoic acid. Once those two form the retinoic acid it stays as retinoic acid.

In order to see in the night we need Rhodopsin which is a light-sensitive protein receptor, it is found in rods of retina.

How Vitamin A help reproductive system?

For male it helps on sperm production and for female help keeping a healthy placenta (pregnancy).

Where can we get it from?

  1. Animal source: fish, liver, eggs, cheese, fish oil, milk.

2. Plant sources: carrot, broccoli, sweet potato, cantaloupe, mango, papaya, most of squashes, corn, spinach, apricot, kale.

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Selected Food Sources of Vitamin A

FoodMicrograms (mcg)
RAE per serving
Percent
DV*
Beef liver, pan fried, 3 ounces (85g)6,582731
Sweet potato, baked in skin, 1 whole1,403156
Spinach, frozen, boiled, ½ cup57364
Pumpkin pie, commercially prepared, 1 piece48854
Carrots, raw, ½ cup45951
Ice cream, French vanilla, soft serve, 1 cup27831
Cheese, ricotta, part skim, 1 cup26329
Herring, Atlantic, pickled, 3 ounces (85g)21924
Milk, fat free or skim, with added vitamin A and vitamin D, 1 cup14917
Cantaloupe, raw, ½ cup13515
Peppers, sweet, red, raw, ½ cup11713
Mangos, raw, 1 whole11212
Breakfast cereals, fortified with 10% of the DV for vitamin A, 1 serving9010
Egg, hard boiled, 1 large758
Black-eyed peas (cowpeas), boiled, 1 cup667
Apricots, dried, sulfured, 10 halves637
Broccoli, boiled, ½ cup607
Salmon, sockeye, cooked, 3 ounces (85g)597
Tomato juice, canned, ¾ cup425
Yogurt, plain, low fat, 1 cup324
Tuna, light, canned in oil, drained solids, 3 ounces (85g)202
Baked beans, canned, plain or vegetarian, 1 cup131
Summer squash, all varieties, boiled, ½ cup101
Chicken, breast meat and skin, roasted, ½ breast51
Pistachio nuts, dry roasted, 1 ounce (28g)
*DV = Daily Value.

Source: Link

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How much vitamin A do we need?

Group/ Intake
*mcg
0-12 months1-3 years4-8 years9-18 yrs19-64 yrs
Tolerance6006009001700-28003000
Female400300400600700
Male500400500700900
* mcg= micrograms

You should be very careful if you take another medicine as vitamin A can interfere with them an cause low blood levels or high level of vitamin A in blood, so you need to avoid taking vitamin A supplements if you already take neomycin, orlistat, or mineral oil.

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Can vitamin A be harmful?

High intakes of some forms of vitamin A can be very harmful for your body.

Getting too much vitamin A from supplements or medicines can cause dizziness, nausea, headaches, coma, even death in severe cases. High intakes of vitamin A in pregnant women can also cause birth defects in their babies, meaning that they should be very careful and need to respect the recommended intake how a healthy pregnancy. Consuming more than 3 times a day the recommended intake can affect your liver and also bone health.

Vitamin A deficiency

Unfortunately more than 500,000 children’s from around the world are blind because of vitamin A deficiency. We don’t want a complete dark world for our kids or anyone’s kids so let’s try and fight against this deficiency by eating clean and controlling our vitamin intake.

Vitamin A deficiency can also lead to infertility and respiratory problems.

If vitamin A isn’t enough from a diet than supplements might be a good source but not too much.

Symptoms of vitamin A deficiency

Is rare but it can happen, here are some signs and symptoms that our body is showing us we have vitamin A deficiency:

  1. Night blindness
  2. Dry skin (eczema and other skin problems)
  3. Dry eyes
  4. Throat and chest infections
  5. Slow healing
  6. Acne
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Here are some useful information about vitamin A. I tried to keep it simple and not too boring. In the following weeks I will talk about vitamin B and everything you need to know about, make sure you follow this blog so you won’t miss any post.

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