Vitamin A for healthy skin, eyes and immune system

Benefits of vitamin A

In the seamless wisdom that only a mother can have, I can still remember my mom giving me and my siblings a dose of cod liver oil on a teaspoon or as a small translucent capsule every winter.

I would gag and make faces but somehow it seemed to go down. She intuitively knew that it was good to take a dose of cod liver oil to help the immune system through the harsh Canadian winters. Now science seems to validate that Cod liver oil, rich in vitamin A, can help the immune system and prevent disease.

Vitamin A was the first vitamin discovered, hence the name. Vitamin A is a collection of related compounds, including retinol, retinal, retinoic acid and carotenoids, the most common of which is beta-carotene. Beta-carotene is basically two vitamin A molecules attached to each other. Beta-carotene is not biologically active and must be converted to vitamin A in the body.

Vitamin A deficiency affects a staggering one in three children worldwide with the highest prevalence in sub-Saharan Africa and southeast Asia. Vitamin A deficiency is primarily caused by lack of dietary intake but is also made worse by infectious digestive diseases. Poor vision, decreased nighttime visual acuity, poor dark adaption, dry eyes and cornea are classic symptoms of vitamin A deficiency. An estimated half million children go blind every year because of a lack of it in their diets.

Foods sources include vitamin A in animal products, such as liver, meat, chicken, fish, eggs and dairy products. Colourful fruits and vegetables, especially orange and yellow ones, are particularly high in vitamin A. Plant sources include carrots, pumpkin, squash, sweet potatoes, bell peppers, dark leafy greens and other vegetables. Carrots and sweet potatoes are believed to be the highest sources of natural vitamin A.

The recommended dietary intake (RDA)of vitamin A for adult males is 900 micrograms (3000 IUs per day) and for adult females, 700 micrograms (2300 IUs per day). For children under 12 years of age, the RDA is less. Vitamin A supplementation less than 1600 micrograms or 5000 IUs per day is considered safe and tolerable.

Vitamin A plays a vital role in eyesight and vision. Rods and cones on the retina require vitamin A to function properly and convert light into electric impulses that create images in our brains. Vitamin A combines with protein opsin to form rhodopsin. When light energy shines on rhodopsin an electric impulse is created and travels via the optic nerve to the optic centre in the brain. Lack of vitamin A causes poor vision, poor visual acuity, poor dark adaption, dry eyes and cornea and is the leading cause of blindness in children under the age of six years.

Vitamin A is also intimately involved in the immune system. It can help to regulate bone marrow to produce white blood cells, increase lymphocyte activity especially T-cells and B-cells, increase innate immunity with natural killer cells and increase adaptive immunity with antibody production.

Vitamin A helps maintain healthy skin by increasing collagen and elastin turnover and production. It also has antimicrobial activity, increases hydration, decreases inflammation, decreases sebum and oil production, decreases dark pigment or age spots. It can also improve skin colour, skin tone, decrease discolouration and spots, wrinkles, sun damage and photoaging.

Mucous membranes are the delicate and moist lining of the mouth, nose, esophagus, lungs and stomach. These membranes are often the first line of defence the body has from invading pathogens. Vitamin A helps to maintain healthy cells that line the mucous membrane.

retinoic acid is the active form of vitamin A. It is usually available by prescription only. Retinol and retinal are inactive forms of vitamin A and must be converted to retinoic acid to be biologically active. Retinol is also available as esters bonded to other molecules for better stability and absorption such us retinyl palmitate and retinyl acetate. Retinol is 20 times less potent that the equivalent dose of retinoic acid. That means a retinoic acid cream of 0.05% is theoretically the same potency as a 1% retinol cream. Retinol creams are usually available OTC or over the counter in potencies from 0.05% to 1%.

A cautionary note, too much vitamin A can be bad, especially to cigarette smokers. In one study, too much vitamin A significantly increased the risk of lung cancer and mortality in smokers and ex -smokers. One possible explanation is vitamin A itself can become a prooxidant and accelerate oxidative damage.

A reasonable approach to supplementation could be to take less than 5,000 IU per day . Another option is to take a pulsed dose occasionally, say once a week for a while during the winter months to help boost immune defences.

Remember, a healthy dose of cod liver oil wasn’t that awful after all.

The information provided in this article does not, and is not intended to, constitute medical advice. All information and content are for general information purposes only.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.

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About the Author

Doug Lobay is a practicing naturopathic physician in Kelowna, British Columbia.

He graduated with a bachelor of science degree from the University of British Columbia in 1987 and then attended Bastyr College of Natural Health Sciences in Seattle, Washington, where graduated with a doctorate in naturopathic medicine degree in 1991. While attending Bastyr College, he began to research the scientific basis of naturopathic medicine. 

He was surprised to find many of the current major medical journals abounded with scientific information on the use of diet, vitamins, nutritional supplements and herbal medicines.

Doug is a member of the College of Naturopathic Physicians of British Columbia and has practiced as naturopathic family physician for more than 30 years.  He maintains a busy practice in Kelowna where he sees a wide age range of patients with various ailments.

He focuses on dietary modification, allergy testing, nutritional assessments, supplement recommendation for optimal health, various physical therapy modalities, various intravenous therapies including chelation therapy.

An avid writer, he has written seven books on various aspects of naturopathic medicine that are available on Amazon and was also a long-time medical contributor to the Townsend Letter journal for doctors and patients, where many of his articles are available to view on-line. He has also given numerous lectures, talks and has taught various courses on natural medicine.

Doug enjoys research, writing and teaching others about the virtues of natural health and good nutrition. When not working, he enjoys cycling, hiking, hockey, skiing, swimming, tennis and playing guitar.

If you have any further questions or comments, you can contact Dr. Lobay at 250-860-7622 or [email protected].

The views expressed are strictly those of the author and not necessarily those of Castanet. Castanet does not warrant the contents.

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