Most Studies Suggest vitamin D3 is More Effective Than D2
For the past several years, the popular “sunshine vitamin” or vitamin D has grabbed headlines for numerous reasons. Foremost is the fact that an estimated three-quarters of all American teens and adults are deficient in vitamin D, a sobering fact considering the deficiency is linked to countless chronic illnesses and life-threatening diseases. There has also been much debate among health professionals about the minimum daily dosage of vitamin D required with some physicians recommending as much as 5,000 – 10,000 IUs per day. Finally, increased interest in the enormous health benefits ascribed to vitamin D has led to more research about how it works and metabolizes in the body, particularly in recent studies suggesting that vitamin D3 is more effective than D2.
You may have never given much thought to the “2” or “3” attached to vitamin D, but they are important because they refer to two inactive precursors. (If you need a quick Biology refresher course, precursors are a substance, cell or chemical component from which another substance, cell or chemical component if formed) In the case of D3, which is known as cholecalciferol, and D2, which is known as ergocalciferol, both are transformed in the liver and kidneys into hydroxyvitamin D, a non-active storage form, and dihydroxyvitamin D, an active form that is controlled by the body. Recent studies have concluded that vitamin D3 is more effective and potent than D2, possibly because of the way the two different forms are metabolized in the body.
One such study reported in the Journal of Clinical Endocrinology & Metabolism and conducted by Robert Heaney, MD, from Creighton University in Nebraska, concluded that vitamin D3 was 87% more potent than D2. Additional studies published in the American Journal of Clinical Nutrition echoed the results of earlier research that D3 is more effective than D2, indicating that vitamin D3 is more effective at raising serum 25 concentrations than vitamin D2. Simply put, researchers determined the difference between the two vitamin D forms is attributed to the way each form is metabolized in the body.
Why should you care about if you are getting enough vitamin D and if you are taking the proper form if you are choosing to supplement? Mainly because most of us do not manufacture enough vitamin D on our own. Some experts blame the increased usage of sunscreen, long sleeves, hats and other precautions to prevent skin cancer as a huge culprit, since applying sunscreen slashes the skin’s ability to produce vitamin D to almost nothing. Winter months exacerbate the problem when some northern countries receive so little sunlight that people are unable to manufacture any vitamin D at all. Add to the fact that many of us spend many hours indoors at office jobs and it’s easy to see why many experts feel that eating vitamin D fortified foods and dietary supplements are the best ways to make sure we’re getting enough vitamin D.
Source: American Journal of Clinical Nutrition