Daily supplementation with 15 μg vitamin D2 compared with vitamin D3 to increase wintertime 25-hydroxyvitamin D status in healthy South Asian and white European women: a 12-wk randomized, placebo-controlled food-fortification trial

Tripkovic L, Wilson LR, Hart K, Johnsen S, de Lusignan S, Smith CP, Bucca G, Penson S, Chope G, Elliott R, Hyppönen E, Berry JL, Lanham-New SA (2017) Am J Clin Nutr. 106(2) 481-490. doi: 10.3945/ajcn.116.138693. Epub 2017 Jul 5.

Web URL: Read this and related abstracts on PubMed here

Abstract:

Background:

There are conflicting views in the literature as to whether vitamin D2 and vitamin D3 are equally effective in increasing and maintaining serum concentrations of 25-hydroxyvitamin D [25(OH)D], particularly at lower doses of vitamin D.

Objectives:

We aimed to investigate whether vitamin D2 or vitamin D3 fortified in juice or food, at a relatively low dose of 15 μg/d, was effective in increasing serum total 25(OH)D and to compare their respective efficacy in South Asian and white European women over the winter months within the setting of a large randomized controlled trial.

Design:

A randomized, double-blind, placebo-controlled food-fortification trial was conducted in healthy South Asian and white European women aged 20-64 y (n = 335; Surrey, United Kingdom) who consumed placebo, juice supplemented with 15 μg vitamin D2, biscuit supplemented with 15 μg vitamin D2, juice supplemented with 15 μg vitamin D3, or biscuit supplemented with 15 μg vitamin D3 daily for 12 wk. Serum 25(OH)D was measured by liquid chromatography-tandem mass spectrometry at baseline and at weeks 6 and 12 of the study.

Results:

Postintervention in the 2 ethnic groups combined, both the vitamin D3 biscuit and the vitamin D3 juice groups showed a significantly greater absolute incremental change (Δ) in total 25(OH)D when compared with the vitamin D2 biscuit group [Δ (95% CI): 15.3 nmol/L (7.4, 23.3 nmol/L) (P < 0.0003) and 16.0 nmol/L (8.0, 23.9 nmol/L) ( P < 0.0001)], the vitamin D2 juice group [Δ (95% CI): 16.3 nmol/L (8.4, 24.2 nmol/L) (P < 0.0001) and 16.9 nmol/L (9.0, 24.8 nmol/L) (P < 0.0001)], and the placebo group [Δ (95% CI): 42.3 nmol/L (34.4, 50.2 nmol/L) (P < 0.0001) and 42.9 nmol/L (35.0, 50.8 nmol/L) (P < 0.0002)].

Conclusions:

With the use of a daily dose of vitamin D relevant to public health recommendations (15 μg) and in vehicles relevant to food-fortification strategies, vitamin D3 was more effective than vitamin D2 in increasing serum 25(OH)D in the wintertime. Vitamin D3 may therefore be a preferential form to optimize vitamin D status within the general population. This trial was registered at www.controlled-trials.com as ISRCTN23421591.

FAB RESEARCH COMMENT:

Findings from this important new clinical trial confirm previous reports that Vitamin D2 (the form of Vitamin D found in some plant foods and supplements, and used in many fortified foods) is not as effective as Vitamin D3 (the form made naturally by the action of sunlight on the skin, and found in some animal-derived foods or Vitamin D supplements) for raising blood levels of Vitamin D

See the associated news article for more details and further links:

Vitamin D3 more effective than D2 - Time to change vitamin D guidelines?

See also this systematic review and meta-analysis of previous clinical trials - addressing the same question of whether Vitamin D2 supplements are as effective as those providing Vitamin D3.

Tripkovic et al 2012 - Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis

This earlier meta-analysis also showed Vitamin D3 to be superior to Vitamin D2 in raising Vitamin D levels.

However, as previous trials were quite heterogeneous, and the available evidence did not address possible confounds (such as method of administration, and ethnicity), the researchers then went on to plan and carry out this latest clinical trial, which was very carefully designed so that it could provide definitive evidence.

These latest findings are particularly important for vegetarians and vegans who rely on the Vitamin D2 form in supplements of fortified foods - as they show that twice the quantity of Vitamin D2 is likely to be needed than has previously been assumed

As the researchers noted, the public health implications of this finding are major - and indicate an urgent need to change current dietary guidelines, which are based on the now-disproven assumption that the two forms are equivalent.

For more information on the importance of adequate Vitamin D for mental as well as physical health, please see the following article lists:

Vitamin D - News

Vitamin D - Research

And for more information on the evidence linking suboptimal Vitamin D status to a wide range of developmental and mental, as well as physical, health conditions - please see the following lists, which are regularly updated.