"In our practice, it is common to see patients treated with vitamin D supplements who do not achieve an appreciable rise in their serum 25OHD level after therapy despite large prescribed doses.
A consistent increase of 50% or greater was seen in the serum 25OHD concentration when patients consumed the vitamin with the largest daily meal."
-Drs. Angelo Licata, MD, PhD. and Guy B. Mulligan, MD., Cleveland Clinic Foundation Metabolic Bone Clinic, "Taking vitamin D with the largest meal improves absorption and results in higher serum levels of 25-hydroxyvitamin D", J Bone Miner Res Feb. 8, 2010 (ahead of print)-
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OK, we all know by now how important it is to raise our vitamin D levels to "optimally" around 50 ng/mL--or at the very least to 32 ng/mL. If you need a refresher in the importance of vitamin D, click here, here, and here.
But guess what? It's easier said than done. I, for one, have found out how slowly those levels really do rise. So what's a person to do--especially if you aren't able to get out into the sun 3 times a week?
All I can say is, "Thank you Dr. Angelo Licata for devising this simple, straightforward research project that's provided an answer for all of us! From now on, I'm taking my vitamin D with my dinner. No more taking it on an empty stomach, on the fly, in between meals!"
Licata and Mulligan figured that since vitamin D is fat-soluble, absorption just might improve if patients took their supplements with their largest meal of the day! How simple is that? See the Iowa State salad dressing/vitamin absorption study
Who participated in this study? There were 17 patients, a mix of men & women, with an average age of 64.5, and an average 25OHD level of 30.5. All were being seen at the clinic for vitamin D deficiency, and they were selected for this study because they were unable to achieve adequate increases in their vitamin D levels despite taking vitamin D supplements. Turns out, all of these patients were taking their vitamin D either on an empty stomach, or with a small meal, usually breakfast or lunch.
This was great mix of patients. Because of different factors, some were on "average" doses of vitamin D, and some were on megadoses. Some were taking D2. Some were taking D3. Some were taking an oil preparation. Some were taking a solid preparation. And all were having difficulty getting their levels up to optimal levels.
- One group was taking about 1,400 IUs of vitamin D3 (either oil or solid capsule) a day, with a baseline 25OHD averaging 28.9
- One group was taking 50,000 IUs of vitamin D2 (oil preparation) per week with a baseline 25OHD averaging 31.3
- One small group of 3 was taking >50,000 (average dose of 183,333 IUs a week) IUs of vitamin D2 (an oil preparation) per week with a baseline 25OHD averaging 32.4
What were the participants asked to do? All 17 participants were told to keep taking their usual vitamin D supplement, but take it with their largest meal of the day, usually dinner.
And the envelope, please. After 2-3 months the participants had their 25OHD levels measured, and everyone ended up with an amazing average increase of around 50% over baseline in their vitamin D levels.
- The 1,400 IUs of D3 folks went from 28.9 before to 45.4 ng/mL after.
- The 50,000 IUs of D2 folks went from 31.3 before to 48.3 ng/mL after.
- The >50,000 IUs of D2 folks went from 32.4 to 48.7 ng/mL after.
Big point: the type of vitamin D preparation taken made no difference--whether it was D2 or D3--oil or solid. All three groups achieved increases over baseline of around 50%.Why concerns about taking high doses of vitamin D are unfounded. Why a Doctors' Care is Critical.
According to Drs. Licata and Mulligan, some patients clearly require very large doses of vitamin D to achieve a mid-range level. They recognize that many physicians are concerned about vitamin D toxicity at such high levels.
"However, it is not the dose prescribed alone which should be considered, but how much is actually absorbed. Some patients require very large doses to achieve mid-normal levels. Monitoring the serum level is critical.
A recent study (click here) indicates that serum concentrations of 25OHD only in the high-normal reference interval prevents non-vertebral fracture. (normal range: 31-80 ng/ML)
Hence, striving to achieve this level (i.e. ~50 ng/mL) may be optimal, rather than a level at the low-end of the normal range."
Thoughts about Citracal: In light of Dr. Licata's study, I couldn't help but think about how many women depend upon getting their vitamin D from Citracal--the calcium/vitamin D capsule that prides itself on being easy-to-take-and-absorbable on an empty stomach!
Limitations to the study: This study was small, there wasn't a control group, and there wasn't a way for the researchers to "know exactly how the patients took their supplements."
"But despite of these limitations, "the results are striking, and consistent across a heterogeneous group of patients (ie different disease states and different preparations and doses of vitamin D).
It therefore seems reasonable to ask patients to take vitamin D supplements with their largest meal, as it may be a cost-effective strategy that could very well help patients achieve optimal serum levels of 25OHD."