Mon | Jun 18, 2018

Beware of low Vitamin D

Published:Tuesday | June 10, 2014 | 12:00 AM

"I think you might dispense with half your doctors if you would only consult Dr Sun more."

- Henry Ward Beecher

VITAMIN D is perhaps the world's most underrated nutrient, made free by your body from sunshine. Perhaps that's why commercial interests do not promote its health benefits.

However, several United Kingdom (UK)-based health groups, including Cancer Research UK, National Osteoporosis Society, Multiple Sclerosis Society, British Association of Dermatologists, Diabetes UK, National Heart Forum and the Primary Care Dermatology Society, have joined to promote the benefits of sunshine and vitamin D.

Vitamin D comes from sunshine

Vitamin D is produced by your skin in response to exposure to ultraviolet radiation (UVR) from natural sunlight, which converts cholesterol in the skin into vitamin D. It is nearly impossible to get enough vitamin D from your diet, and sunlight exposure is the most reliable source. You would need to drink quarts of vitamin D fortified milk every day to get minimum levels of vitamin D.

On the other hand, in a one-hour sunbath, the body can manufacture up to 10,000 units of vitamin D, or five times the recommended daily allowance. It is impossible for your body to make too much vitamin D from sunlight exposure: your body self-regulates and only produces what it needs.

Black people need more sunshine

The darker your skin colour, the more sunshine you need to make vitamin D because the pigment melanin acts as a powerful sunscreen. People with dark skin may need as much as eight times more sunlight than fair-skinned people to generate the same amount of vitamin D. Because of this, many black persons are vitamin D deficient. Research shows that more than 90 per cent of African Americans and more than 80 per cent of black people living in the UK are vitamin D deficient. Many Jamaicans also have this deficiency in spite of living on a sun-drenched island. Also, the further you live from the equator, the more sunshine you need in order to generate vitamin D.

Vitamin D and cancer

Sunlight itself does not cause cancer. In fact, compelling medical evidence indicated that vitamin D could prevent up to 80 per cent of some types of cancer. The research clearly demonstrates that the lower your vitamin D levels in your blood, the higher your risk of developing several cancers. Fifteen cancers have been identified as vitamin D-sensitive: colon, stomach, oesophagus, gallbladder, rectum, small intestine, bladder, kidney, prostate, breast, endometrium, ovary, Hodgkins and non-Hodgkins lymphoma. The researchers reliably predicted that hundreds of thousands of cancers could be prevented around the world by raising the vitamin D levels in entire populations.

Vitamin D and bones

Much is made of the need for sufficient dietary calcium to ensure strong bones and to prevent osteoporosis. It must, however, be equally emphasised that vitamin D is critical for calcium to be absorbed in the intestines. Without sufficient vitamin D, your body cannot absorb calcium, rendering calcium supplements useless. Much of the current epidemic of osteoporosis is related to vitamin D deficiency. Optimal vitamin D levels reduce the risk of hip fractures in the elderly by 25 per cent.

Vitamin D and infections

Vitamin D improves immune function and provides protection against infections. Both bacterial diseases like pneumonia, gingivitis, septicemia and tuberculosis, as well as viral diseases like influenza and the common cold, are influenced by vitamin D. Influenza outbreaks are seasonal in part due to variations in sunshine levels and vitamin D. The vitamin also has a protective effect against autoimmune disorders, particularly Type 1 diabetes and multiple sclerosis.

Vitamin D and metabolic diseases

There is growing evidence that vitamin D reduces the risk of the common metabolic diseases including coronary heart disease, Type 2 diabetes, hypertension and stroke. This may be part of the reason why these disorders are so prevalent in black populations like African Americans and Caribbean peoples.

Optimise your D

Chronic vitamin D deficiency cannot be reversed overnight. It takes months of sunlight exposure and vitamin D supplementation to build up the body's levels. I strongly recommend a daily sunbath whenever possible for everyone. Ideally, one should try to expose at least 50 per cent of your skin directly to the sun for at least 30 minutes. The UVB rays of natural sunlight that generate vitamin D production cannot penetrate glass, so you don't make vitamin D when sitting behind the window in your car or home. Sunscreens block your body's ability to generate vitamin D by up to 95 per cent. The use of sunscreen products may actually promote vitamin D deficiency in the body.

Whether from sunshine, food or supplements, Vitamin D must first be 'activated' in your body by your kidneys and liver before it becomes useful. Individuals with kidney or liver damage are prone to vitamin D deficiency. The elderly make vitamin D less efficiently, so the old need more sunshine and benefit from vitamin D supplements.

What about sunburn, skin damage and skin cancer?

Antioxidants greatly boost your body's ability to handle sunlight without damage or burning. In addition to sensible sunbathing, take enough vitamins A, C and E and eat lots of fresh fruit and vegetables. This is particularly important if you have fair or sensitive skin. Remember that melanin, the pigment that makes skin black, is itself a powerful antioxidant and so people of colour have much less risk of those problems.

You may email Dr Tony Vendryes at or listen to 'An Ounce of Prevention' on POWER 106FM on Fridays at 8 p.m. His new book 'An Ounce of Prevention, Especially for Women' is available locally and on the Internet.