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No long term differences in vitamin D levels with amount of fat in breakfast – Feb 2013

Meal conditions affect the absorption of supplemental vitamin D(3) but not the plasma 25-hydroxyvitamin D response to supplementation.

J Bone Miner Res. 2013 Feb 20. doi: 10.1002/jbmr.1896.
Dawson-Hughes B, Harris SS, Palermo NJ, Ceglia L, Rasmussen H.
Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, 711 Washington St., Boston, MA 02111. Bess.dawson-hughes at tufts.edu.

It is sometimes assumed that dietary fat is required for vitamin D absorption, although the impact of different amounts of dietary fat on vitamin D absorption is not established. This study was conducted to determine whether the presence of a meal and the fat content of the meal influences vitamin D absorption or the 25-hydroxyvitamin D (25OHD) response to supplemental vitamin D(3) . Based on earlier studies in rats we postulated that absorption would be greatest in the low-fat meal group. Sixty two healthy older men and women were randomly assigned to one of three meal groups: no meal, high-fat meal or low-fat meal; each was given a monthly 50,000 IU vitamin D(3) supplement with the test breakfast meal (or after a fast for the no-meal group) and followed for 90 days. Plasma vitamin D(3) was measured by LC/MS before and 12 hrs after the first dose; plasma 25OHD was measured by radioimmunoassay at baseline and after 30 and 90 days.

The mean 12-hr increments in vitamin D(3) , after adjusting for age and sex, were

  • 200.9 nmol/L in the no-meal group,
  • 207.4 nmol/L in the high-fat meal group, and
  • 241.1 nmol/L in the low-fat meal group (P = 0.038),

with the increase in the low-fat group being significantly greater than the increases in the other two groups.

However, increments in 25OHD levels at 30 and 90 days didn't differ significantly in the three groups.

We conclude that absorption was increased when a 50,000 IU dose of vitamin D was taken with a low-fat meal, compared with a high-fat meal and no meal, but that the greater absorption didn't result in higher plasma 25OHD levels in the low-fat meal group. © 2013 American Society for Bone and Mineral Research.

Copyright © 2013 American Society for Bone and Mineral Research. PMID: 23427007

Items not covered in abstract were answered by the author via email

  1. Was the vitamin D in oil?
    No - it was in dry form in capsules.
  2. What were the levels at 30 days?
    Serum 25OHD was measured on days 1, 30 and 90 only; and vitamin D3 on day 1 only
  3. How much difference vs age
    In an earlier study, we saw no effect of age on vit D or 25OHD responses to supplementation with 800 IU per day of vitamin D
    Plasma vitamin D responses of young and old men to supplementation with 20 mg of vitamin D3 2002 full text online

See also VitaminDWiki

see wikipage http://www.vitamindwiki.com/tiki-index.php?page_id=1046