There are two types of vitamin D, which are known as D-2 and D-3. The former is derived from plant sources, particularly fungi, while the latter comes from animal sources. The two types of vitamin D are very similar, differing only in the structure of their side-chains, and it is generally accepted that both perform similarly well as a supplement. In fact, on the National Institutes of Health website, they write, "The two forms have traditionally been regarded as equivalent." Researchers from the University of Surrey in the United Kingdom recently set out to test whether or not this widely held belief is correct. They wanted to understand which of the two nutrients raises levels of vitamin D in the body most effectively. The researchers measured vitamin D levels in 335 South Asian and white European women over two winter periods. They chose winter because, due to a reduction in sunlight exposure, vitamin D levels tend to be lower at this time. The women were split into five groups: those consuming vitamin D-2 in a biscuit; those consuming vitamin D-3 in a biscuit; those consuming vitamin D-2 in a juice drink; those consuming vitamin D-3 in a juice drink; and those receiving a placebo. For More Details Startup Marketing Video