Oil-based Vitamin D3 has the worst bioavailability – April 2014

Impact of Vitamin D3 Dietary Supplement Matrix on Clinical Response

Michael L. Traub, John S. Finnell, Anup Bhandiwad, Erica Oberg, Lena Suhaila, and Ryan Bradley
JCEM DOI: http://dx.doi.org/10.1210/jc.2013-3162, Published Online: March 31, 2014

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Context: As a result of research suggesting increased health risk with low serum 25-hydroxycholecalciferol (25(OH)D), healthcare providers are measuring it frequently. Providers and patients are faced with treatment choices when low status is identified.

Objective: To compare the safety and efficacy of three vitamin D3 dietary supplements with different delivery matrices.

Design & Setting: 12-week, parallel group, single-masked, clinical trial conducted in Seattle, WA and Kailua Kona, HI.

Participants & Intervention: 66 healthy adults with (25(OH)D) < 33 ng/ml were randomly assigned to take one of three D3 supplements, i.e., a chewable tablet (TAB), an oil-based drop (DROP) or an encapsulated powder (CAP), at a label-claimed dose of 10,000 IU/day. Actual D3 content was assessed by a third-party, and the results adjusted based on the actual D3 content administered.

Main Outcome Measures:
mean change in 25(OH)D/mcg D3 administered; difference in the proportion of D3 insufficient participants (i.e., 25(OH)D ≤30ng/ml) reaching sufficiency (i.e., 25(OH)D ≥30ng/ml); and mean change in serum 1, 25-dihydroxycholecalciferol.

Results:
In two of the three products tested, the measured vitamin D3 content varied considerably from the label-claimed dose. Differences in 25(OH)D/mcg D3 administered were significantly different between groups (p=0.04; n=55). Pairwise comparisons demonstrated DROP resulted in a greater increase than TAB (p<0.05) but not than CAP. TAB was not different from CAP.
The proportions reaching sufficiency were:

• 100% (TAB and CAP) and
• 80% (DROP) (p=0.03 between groups, n=55).

1, 25-dihydroxycholecalciferol did not change significantly in any group.

Conclusions: Oil-emulsified vitamin D3 supplements resulted in a greater mean change in serum 25(OH)D concentration, but fewer patients reaching vitamin D sufficiency, than chewable or encapsulated supplements.

Affiliations: Lokahi Health Center, Kailua Kona, HI, USA; AOMA Graduate School of Integrative Medicine; Austin, TX, USA; Wayne State University, Detroit, MI, USA; Pacific Pearl Center for Health and Healing; La Jolla, CA, USA; Cancer Treatment Centers of America Western Regional Medical Center; Phoenix, AZ, USA; Bastyr University Research Institute; San Diego, CA, USA