FAB RESEARCH COMMENT:
This important new clinical trial confirm previous reports that Vitamin D2 (the form 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 story for more details and further links:
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.
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.
As the researchers noted, the public health implications of this finding are major - and indicate an urgent need to change current dietary guidelines.