Taking Vitamin D Supplements with Meals

Dr. Michael Greger’s Latest in Clinical Nutrition 6 is now available! In it, he mentions a study about taking vitamin D with meals. I’ve wondered if doing this would help people whose vitamin D levels seem to be resistant to supplementation and so I tracked down the study and updated the VeganHealth.org article, Bones, Vitamin D, and Calcium:

Because vitamin D is a fat soluble vitamin, taking vitamin D supplements with foods that contain fat might increase absorption.

A 2010 study explored this (1). A group of people diagnosed with vitamin D deficiency had been prescribed supplements (some D2 and some D3) and were being monitored by the Cleveland Clinic Foundation Bone Clinic. Some of these patients’ vitamin D levels had not increased to desired levels. Patients with stubborn vitamin D levels were then instructed to take the vitamin D with meals. After 2 to 3 months of taking with meals, the average vitamin D level went from 30 to 47 ng/ml (75 to 117 nmol/l).


PeaCounter.com ‒ Nutrient Composition of Foods & Diet Analysis

This study had no control group, so it is not clear that the vitamin D levels increased due to taking with meals. It could have been simply because their levels took longer to respond to supplements or because they were exposed to more sunlight during the meal period (the time of year studied was not reported). It should also be noted that even though these subjects’ vitamin D levels were more stubborn than other patients, their levels at the beginning of the study were well above those recommended by the Institute of Medicine (16-20 ng/ml or 40-50 nmol/l) the stubborn levels might have been a result of the body regulating vitamin D once it had reached an ideal level rather than an inability to absorb it.

Reference

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

5 Responses to “Taking Vitamin D Supplements with Meals”

  1. theveganscientist Says:

    I’ve wondered about this, as every vegan I know (N ~20) that has been tested for Vit D deficiency, has come up deficient usually in the 5-20ng/mL range.

    I was wondering if you have found any information concerning the metabolic conversion of ergocalciferol to 25-hydroxycholecalciferol or if it is converted to 25-hydroxyergocalciferol and ultimately to 1,25-dihydroxyergocalciferol. I can’t seem to find anything definitive.

    If there is no conversion from ergocalciferol to cholecalciferol, I would expect them to have different enzymatic conversion rates and different binding affinities based on geometrical and electronic differences due to the the extra methyl group and double bond on ergocalciferol.

    Additionally, if the blood work is analyzed via LC-MS, do they count both analogs in their report, or do they only quantitate the1,25-dihydroxycholecalciferol form?

    I’ve also read somewhere that ingesting large amounts of ß-carotene competes with Vitamin D storage in the liver. Do you believe these all may be a factor in Vitamin D status? Given vegans tend to eat lots of veggies, do you think this might also exasperate their poor vitamin D status?

    I just got my blood tested for Vit D and am expecting results. It’s been a real struggle for me to get adequate blood levels with D2 supplements. I just ordered some Vistashine and will use that for a month (same dose 2000IU/day), and retest.

  2. Jack Norris RD Says:

    theveganscientist,

    > usually in the 5-20ng/mL range.

    The Institute of Medicine recommends a range of 16-20 ng/ml, so some of these people might not actually be deficient. I recently had mine tested and it was 34 ng/ml.

    > it is converted to 25-hydroxyergocalciferol and ultimately to 1,25-dihydroxyergocalciferol.

    That is my understanding.

    > Additionally, if the blood work is analyzed via LC-MS, do they count both analogs in their report, or do they only quantitate the1,25-dihydroxycholecalciferol form?

    Good question. My assumption has been that they count both and they certainly count both in many of the studies I’ve read. But if some labs don’t count ergo-, that would explain some vegans’ levels being too low! But why would a doctor prescribe D2 (which they often do) and then retest only D3? I’m guessing they always measure both but would be interested to know if that’s true.

    > Given vegans tend to eat lots of veggies, do you think this might also exasperate their poor vitamin D status?

    Interesting but I doubt it. Only pre-formed vitamin A has been associated with poor bone health:

    http://lpi.oregonstate.edu/infocenter/vitamins/vitaminA/

  3. Betty Says:

    When they are talking about nutrient interactions, are they using supplement-type sources or food, and are they using people or animals to find out just what is going on? I’m darned if I’m going to knock myself out reading entire scientific studies to see what these folks are up to.

  4. Jack Norris RD Says:

    Betty,

    I’m not sure what you are specifically referring to here, and I’d need to know in order answer your question. The vitamin D study mentioned above used vitamin D supplements in humans.

  5. Zak Says:

    Hi Jack -

    just read this http://www.vitasearch.com/get-clp-summary/39995. Talks about absorption of Vitamin D supplementation depending on types of dietary fats (MUFAs vs. PUFAs) ingested.

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