According to the US-based Vitamin D Council, a non-profit organisation responsible for spreading reliable information on vitamin D, sun exposure, and the vitamin D deficiency pandemic, vitamin D deficiency is estimated to affect a third to half of the adult population worldwide.
Living in tropical Malaysia does not mean we are getting enough of the sunshine nutrient - vitamin D3. Factors affecting vitamin D production from sunlight range from the angle of the sun's rays, the time of the day, skin type, etc.
Vitamin D3 is known for helping with calcium absorption, and for building strong bones, which is why milk has been fortified with it.
But there is growing evidence to show that vitamin D deficiency is linked with numerous other health conditions and diseases, from cancer to heart disease, high blood pressure and diabetes.
The heart health connection
Getting enough vitamin D3 may help your heart, according to a study published in the January 2008 publication of the Journal of American Heart Association. Researchers found that people with the lowest levels of vitamin D were more likely to have a heart attack, stroke, angina or heart failure, than those who started with higher vitamin D levels.
In a randomised controlled trial consisting of 77 overweight and obese women carried out in Tehran, Iran, vitamin D supplementation has shown potential in regards to improving blood lipid profiles.
Based on a study focusing on the effects of vitamin D on heart health, conducted at the Intermountain Medical Centre based in Salt Lake City in the US, involving 27,686 patients, those with the lowest vitamin D levels were 77 per cent more likely to die during the follow-up, 78 per cent more likely to have a stroke and 45 per cent more likely to develop coronary artery disease than those with normal levels. They were twice as likely to develop heart failure compared to those with normal levels.
And even those who had moderate deficiencies were at higher risk, the researchers said.
People who were vitamin D deficient were also twice as likely to have diabetes, and tended to have high blood pressure. But being vitamin D deficient was an independent risk factor for poor outcomes, regardless of other risk factors like diabetes, said Dr Joseph B. Muhlestein, cardiologist and researcher with Intermountain Medical Centre, and one of the authors of the new study.
He adds: "What we were taught in medical school about vitamin D is that it's associated with rickets and calcium metabolism."
That, however, is changing. "What's been discovered in the last few years is a significantly greater role for vitamin D," Dr Muhlestein said. "There are perhaps 200 different important metabolic processes that use vitamin D as a co-factor."
How do you get your vitamin D?
There are only two ways to receive vitamin D in the amounts necessary for proper health: ultraviolet B (UVB) exposure and vitamin D supplementation. Diet should not be considered a satisfactory source of vitamin D. The few foods that do contain vitamin D, contain too little to have any noticeable benefit.
Vitamin D3 (cholecalciferol) is the type of vitamin D the body naturally produces in the skin in response to sun exposure. Vitamin D2 is produced naturally when fungi (yeast or mushrooms) are exposed to ultraviolet light from the sun, or to artificial UV light. There is evidence that the body has preference for D3 over D2, showing in these studies that the body more readily uses D3 when it has both forms in the body, and that D3 is more potent than D2 for producing 25(OH)D.
The safety limit for vitamin D is much higher than commonly believed. Based on the latest evidence, it is determined that 10,000 I.U. a day is non-toxic. After all, your body can easily make 20,000 I.U. after 30 minutes at the beach between 10am and 2pm.
Published cases of toxicity, for which serum levels and doses are known, all involve intake of over 40,000 IU (1,000 mcg) per day. Many health experts recommend 1,000 I.U. to 2,000 I.U. of vitamin D3 supplements a day for the prevention of many heart-related conditions.
When taking a vitamin D supplement, try to choose a supplement made with natural vitamin D3 (cholecalciferol).