There are two types of vitamin D, D2 and D3 - the former is produced by plants and the latter is derived from animal products and is also made by your skin when it's exposed to light.
Up until this latest study, which will be published in this month's American Journal of Clinical Nutrition, it's been largely thought that both perform well as a supplement however for the first time scientists from the University of Surrey set out to find out if one raises vitamin D levels in the body more effectively than the other.
People who aim to consume more D3 are twice as likely to raise their vitamin D levels
The findings suggest that people who aim to consume more D3 through eating fish, eggs or taking supplements will be twice as likely to raise their vitamin D levels compared to those only consuming vitamin D2 rich-foods such as mushrooms, fortified bread or D2 containing supplements.
Over two winters, the researchers studied over 300 women from South Asia and Europe and split the participants in to five groups.
The women either consumed vitamin D2 in a biscuit or drink, vitamin D3 in a biscuit or drink, or were given a placebo.
Those who had the form D3 in a biscuit raised their vitamin D levels by 74%, while those having the vitamin D3 in the juice saw their levels rise by 75%.
However, the women who had D2 in a biscuit and juice, saw levels rise by 33-34% and the placebo group saw their levels drop by 25%.
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.
Lead author Dr. Laura Tripkovic explains:
"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.
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."
Findings not in line with current guidance
Current guidelines given by a number of Government bodies around the world – including the US National Institute of Health – say that the two forms of vitamin D are equivalent and can be used to equal effect.
Further to this, recent figures from Public Health England showed that more than 1 in 5 people in the UK have low levels of vitamin D.
In light of this new advice from Public Health England in 2016 states is that adults and children over the age of one should take a daily supplement containing 10mcg of vitamin D, particularly during autumn and winter.
However it does not differentiate between which form to take - the researchers now say it should as daily consumption of vitamin D3 will help people avoid health problems such as osteoporosis, rickets and increased risk of cardio vascular disease.
Principal investigator professor Susan Lanham-New said:
'This is a very exciting discovery which will revolutionise how the health and retail sector views vitamin D. 'Vitamin D deficiency is a serious matter, but this will help people make a more informed choice about what they can eat or drink to raise their levels through their diet.'