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Dietary fat increases vitamin D-3 absorption

Bess Dawson-Hughes, Susan S Harris, Alice H Lichtenstein, Gregory Dolnikowski, Nancy J Palermo, Helen Rasmussen

Journal of the Academy of Nutrition and Dietetics 2015 115(2):225-230

Bibliography

PubMed: PMID 25441954
DOI: 10.1016/j.jand.2014.09.014
Funding: Funding is not specified in the indexed abstract or accessible funding metadata. Consult the original publication for the declaration.
Competing interests: A competing-interest declaration is not available in the indexed abstract or accessible disclosure metadata.

Study snapshot

Design	Open, randomized, single-dose absorption experiment
Model	Human participants
Sample	50 healthy older adults
Intervention	Single 50,000 IU D3 dose with a fat-free or fat-containing breakfast
Duration	1 day; measurements through 14 hours
Endpoints	Peak plasma vitamin D3 concentration

What the study showed, in plain terms

This publication examines peak plasma vitamin d3 concentration. Study population or evidence base: 50 healthy older adults. Intervention or exposure: Single 50,000 IU D3 dose with a fat-free or fat-containing breakfast.

Key findings

Taking D3 with a fat-containing meal increased peak circulating vitamin D3 compared with a fat-free meal. The tested fat composition did not significantly change absorption.

What this study can and cannot tell us

An acute high-dose absorption experiment. It does not show that a large or high-fat meal is necessary for every dose, formulation or person.

Citation network

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Biohack Blueprint analyses that reference this study in their evidence base.

Oct 17, 2026 When to Take Vitamin D3, K2 and Magnesium: Together, Food or Night?When to take D3, K2 and magnesium: meals, morning or night, study schedules, medicine spacing and practical daily examples.Read analysis

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