If you are taking vitamin D supplements does it matter how and when you take your pills or drops? Recent research suggests yes: Take them with the largest meal of the day. And for most of us, that’s dinner.

Researchers at the Cleveland Clinic Bone Clinic wondered why it was that some of the patients with vitamin D deficiency failed to increase their vitamin D blood levels (25-hydroxy D) when put on supplements and retested 2-3 months later.  Normally, when you start to take vitamin D supplements, blood levels slowly climb and then plateau. Continuing on with the same dose of vitamin D will not substantially increase blood levels after this point.

So the researchers asked a group of vitamin D non-responders to take their usual vitamin D supplement with the biggest meal they ate each day. After 2-3 months average serum 25 hydroxy D levels had increased from 76.25 nmol/L +/- 11.75 (30.5 +/- 4.7 ng/mL) to 118 +/-  27.25 nmol/L (47.2 +/- 10.9 ng/mL), an increase of more than 50%. The patients were on a variety of doses of vitamin D ranging from 1000-50,000 IUs a day. But the dose didn’t seem to matter, as the approximate improvement in vitamin D status was similar for all.

And the improvements were not just seen in patients with bone disorders (osteoporosis or osteopenia). Researchers report that similar increases were observed with a wide range of vitamin D doses taken for a variety of medical conditions.

Reference: Taking vitamin D with the largest meal improves absorption and results in higher serum levels of 25-hydroxyvitamin D. Mulligan GB, Licata A. J Bone Milner Res. 2010;25(4):928-30