06 Jul 2017 --- A groundbreaking study from the University of Surrey has dispelled the myth that vitamin D2 and D3 have the same nutritional value, raising serious questions marks with regards to official guidance around vitamin D. This finding not only has implications for the health sector but also for the retail market. In the belief that it will help a person fulfill their daily intake, many retailers have over the past few years added vitamin D2 to their products. This study, however, has proven that D3 is the most effective form of increasing vitamin D levels in the body.

Using low doses of vitamin D in fortified food, the researchers looked into which of the two types of vitamin D – D2 or D3 – was more effective in raising levels of this vital nutrient in the body. Vitamin D3 is derived from animal products, while D2 is plant-based.

Researchers examined the vitamin D levels of 335 South Asian and white European women over two consecutive winter periods, a time when the nutrient is known to be lacking in the body. The women were split into five groups, with each group receiving either a placebo, a juice containing vitamin D2 or D3 and a biscuit with D2 or D3.

Vitamin D3 was discovered to be twice as effective in raising levels of the vitamin in the body than its counterpart D2. Vitamin D levels in women who received vitamin D3 via juice or a biscuit increased by 75 percent and 74 percent, respectively, compared to those who were given D2 through the same methods. The participants given D2 saw an increase of 33 percent and 34 percent over the course of the 12-week intervention.

The research also found that nutrient levels of both vitamin D2 and D3 rose as a result of both food and acidic beverages such as juice, which were found to be equally as effective. Those who received the placebo experienced a 25 percent reduction in the vitamin over the same period.

Current guidance given by a number of government bodies around the world, including the US National Institute of Health, states that the two forms of vitamin D are equivalent and can be used to equal effect.

Latest figures from Public Health England has found that more than 1 in 5 people in the UK have low levels of vitamin D and has increased the recommended intake of the vitamin to 10 micrograms per day, throughout the year, for everyone in the general population aged 4 years and older. Daily consumption of products containing vitamin D3 but not vitamin D2 will enable the population to meet this target helping to avoid the health implications such as osteoporosis, rickets and increased risk of cardio vascular disease which are associated with insufficient levels of vitamin D in the body.

“The importance of vitamin D in our bodies is not to be underestimated, but living in the UK it is very difficult to get sufficient levels of it from its natural source, the sun, so we know it has to be supplemented through our diet,” notes lead author Dr. Laura Tripkovic from the University of Surrey.

“However, our findings show that vitamin D3 is twice as effective as D2 in raising vitamin D levels in the body, which turns current thinking about the two types of vitamin D on its head. Those who consume D3 through fish, eggs or vitamin D3 containing supplements are twice as more likely to raise their vitamin D status than when consuming vitamin D2 rich foods such as mushrooms, vitamin D2 fortified bread or vitamin D2 containing supplements, helping to improve their long-term health,” Tripkovic says.

“This is a very exciting discovery which will revolutionize how the health and retail sector views vitamin D,” says Professor Susan Lanham-New, Head of the Department of Nutritional Sciences at the University of Surrey and Principal Investigator of the BBSRC DRINC funded trial.