Vitamin D3 May Be Superior to Vitamin D2 for Supplementation
The importance of vitamin D has been known for many years. In fact, many countries add it to staple foods to ensure it is consumed by their citizens. There are two precursors of vitamin D that are commonly used as supplements: D2 and D3. A new meta-analysis shows that vitamin D3 is better than D2 at increasing blood levels of vitamin D.
This was the first meta-analysis and systematic review to address this topic. The research was conducted at the University of Surrey, England and was published online ahead of print on May 2, 2012, in The American Journal of Clinical Nutrition.
When you take a vitamin D supplement or eat vitamin D rich foods, you're ingesting one of two biologically inactive precursors: vitamin D3 and vitamin D2. Your kidneys and liver then transform the vitamin into two different forms. The first is 25-hydroxyvitamin D (25(OH)D), which is the non-active storage form. The second is1,25-dihydroxyvitamin D, which is the biologically active form of the vitamin.
The researchers examined 7 randomized controlled trials and determined that vitamin D3 was more effective at raising blood levels of 25(OH)D than vitamin D2. . As the body has more vitamin D available in storage form, the chance of deficiency reduces.
The researchers believe that the differences in absorption could be a result of the fact that the body metabolizes the two vitamin D forms differently. They noted, however, that more research needs to be conducted to determine the exact ways that vitamin D is delivered to the blood stream.
Previous research has linked vitamin D with a vast number of health benefits, including reducing the risk of skin cancer and osteoporosis, improving cardiovascular health, combating diabetes, and improving age related eye degeneration.
Dietary vitamin D can be found in milk, fortified cereals, fish, and eggs. A high quality vitamin D supplement is always a good option if you feel that you’re not getting enough through diet and sun.