Best form of vitamin d for absorption
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Best Form of Vitamin D for Absorption
Introduction to Vitamin D Absorption
Vitamin D is essential for various bodily functions, including bone health, immune function, and calcium absorption. However, the efficiency of vitamin D absorption can vary based on several factors, including the form of vitamin D and dietary components. This article synthesizes current research to determine the best form of vitamin D for optimal absorption.
Forms of Vitamin D: D2 vs. D3
Vitamin D exists in two primary forms: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Research indicates that both forms are absorbed with similar efficiency . However, the metabolite 25-hydroxyvitamin D (25OHD), which is produced in the liver and can be found in some foods, is absorbed more efficiently than both D2 and D3 .
Impact of Dietary Fat on Vitamin D Absorption
Several studies have shown that the presence of dietary fat significantly enhances the absorption of vitamin D. A study involving healthy older adults demonstrated that taking vitamin D3 with a fat-containing meal increased plasma vitamin D3 levels by 32% compared to a fat-free meal . This finding is supported by a systematic review, which concluded that vitamin D absorption is better when consumed with fat-containing meals . However, the type of fat (monounsaturated vs. polyunsaturated) does not appear to significantly influence absorption .
Bioavailability and Food Matrix
The food matrix, or the composition of the food with which vitamin D is consumed, has little effect on its bioavailability . This suggests that while the presence of fat is crucial, the specific type of food may not be as important.
Factors Affecting Vitamin D Absorption
Other factors that can influence vitamin D absorption include the presence of certain substances that modify cholesterol absorption, such as sucrose polyesters (Olestra) and tetrahydrolipstatin (orlistat), which likely diminish vitamin D absorption . Additionally, genetic variations in proteins involved in vitamin D absorption and the individual's vitamin D status may also play roles, although data on these factors are limited .
Conclusion
In summary, the best form of vitamin D for absorption appears to be 25-hydroxyvitamin D (25OHD), given its higher absorption efficiency compared to D2 and D3. Additionally, consuming vitamin D with a fat-containing meal significantly enhances its absorption, although the type of fat does not seem to matter. Further research is needed to explore other potential factors affecting vitamin D absorption, such as genetic variations and the impact of dietary fibers. For optimal vitamin D absorption, it is advisable to take supplements with meals that include some fat.
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