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Vitamin D3 more effective than D2 in preventing deficiency

Vitamin D3 is superior to vitamin D2 in raising total vitamin D levels and thus may be the preferential form to prevent deficiency and optimize vitamin status, according to a study published in the American Journal of Clinical Nutrition.

As a result of these findings, the researchers are urging worldwide health authorities to rethink official guidelines that maintain that vitamin D2 and vitamin D3 have the same nutritional value and produce equal outcomes.

“There are conflicting views in the literature as to whether vitamin D2 and vitamin D3 are equally effective at raising and maintaining serum concentrations of 25-hydroxyvitamin [25(OH)D], particularly at lower doses of vitamin D,” Laura Tripkovic, PhD, from the department of nutritional sciences at the University of Surrey in England, and colleagues wrote.

Tripkovic and colleagues conducted a double-blind, food fortification trial to investigate how effective low doses of vitamin D2 and vitamin D3 were in raising serum total 25(OH)D. Over two consecutive winter periods, they enrolled 335 healthy South Asian and white European women aged between 20 and 64 years and randomly assigned them to receive either a placebo, juice containing 15 g of vitamin D2 or D3 or a biscuit containing 15 g of vitamin D2 of D3 daily for 12 weeks. The researchers used liquid-chromatography tandem spectrometry to measure serum 25(OH)D at baseline, week 6 and week 12.

The D3 biscuit and D3 juice groups showed significantly greater absolute incremental change in total 25(OH)D compared with the D2 biscuit and D2 juice groups among both ethnic groups. Vitamin D3 was twice as effective as vitamin D2 in increasing levels of the vitamin within the body, the researchers found. Vitamin D levels were raised by 75% and 74% in participants receiving vitamin D3 via juice or a biscuit, respectively, compared with those receiving vitamin D2 via the same method. Participants who received vitamin D2 through juice or biscuit experienced a 33% and 34% increase in vitamin D, respectively. Conversely, those who received a placebo displayed a 25% decline in vitamin D.

“The importance of vitamin D in our bodies is not to be underestimated,” Tripkovic said in a related press release.

“Our findings ... turn current thinking about the two types of vitamin D on its head,” she continued. “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.”

Although vitamin D3 may be most beneficial for individuals with baseline serum 25(OH)D below 50 nmol/L, both forms of vitamin D in fortified food are effective at increasing levels of the vitamin in the body, as well as preventing deficiency, the researchers noted.

“This is a very exciting discovery which will revolutionize how the health and retail sector views vitamin D,” Susan Lanham-New, BA, MSc, PhD, coauthor and head of the department of nutritional sciences at the University of Surrey, said in the release.

“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,” she added. – by Alaina Tedesco

Disclosure: The researchers report that this study was supported by the UK-based Biotechnology and Biological Sciences Research Council.