What helps absorb vitamin d3
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Factors Influencing Vitamin D3 Absorption
Vitamin D3, also known as cholecalciferol, is essential for maintaining bone health and supporting the immune system. Understanding the factors that influence its absorption can help optimize its benefits. This article synthesizes current research on what helps absorb vitamin D3 effectively.
Sunlight Exposure and Vitamin D3 Synthesis
Ultraviolet B Radiation
Sunlight is a primary source of vitamin D3. Ultraviolet B (UVB) photons from the sun are absorbed by 7-dehydrocholesterol in the skin, converting it to previtamin D3, which is then transformed into vitamin D32 7. Factors such as season, latitude, time of day, skin pigmentation, and sunscreen use significantly affect the cutaneous production of vitamin D32 7.
Sensible Sun Exposure
Moderate sun exposure, typically 5-10 minutes of sunlight on the arms and legs or face, 2-3 times per week, is recommended to maintain adequate vitamin D levels2. However, excessive sun exposure should be avoided due to the risk of skin cancer2.
Dietary and Supplemental Vitamin D3
Forms of Vitamin D
Vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol) are the two main forms used in supplements and fortified foods. Both forms are absorbed with similar efficiency3. However, 25-hydroxyvitamin D (25OHD), a metabolite of vitamin D3, is better absorbed than the non-hydroxy forms3.
Fat Intake
Vitamin D3 is a fat-soluble vitamin, and its absorption is enhanced when consumed with fat-containing meals4. However, absorption can still occur without fat or oily vehicles, although less efficiently4.
Food Matrix and Bioavailability
The food matrix, or the composition of the food in which vitamin D is consumed, has little effect on its bioavailability3. However, substances like sucrose polyesters (Olestra) and tetrahydrolipstatin (orlistat) can diminish vitamin D absorption3.
Vitamin D3 Analogues and Intestinal Absorption
Direct Stimulation of Vitamin D Receptors
Certain vitamin D3 analogues, such as eldecalcitol (ELD) and 1α hydroxyl calcidiol (ALF), have been shown to significantly increase intestinal fractional calcium absorption (FCA) by directly stimulating vitamin D receptors in the intestine1. These analogues are more effective than plain vitamin D3 in enhancing FCA1.
Factors Affecting Vitamin D3 Absorption Efficiency
Cholesterol Transporters
Recent research suggests that vitamin D3 absorption involves both passive diffusion and mechanisms involving membrane carriers, particularly cholesterol transporters4. Factors that modify cholesterol absorption also influence vitamin D3 absorption4.
Genetic and Physiological Factors
There is insufficient data on how genetic variations and physiological factors like aging affect vitamin D3 absorption. However, it is known that aging does not significantly impact vitamin D3 absorption efficiency3.
Conclusion
Optimizing vitamin D3 absorption involves a combination of sensible sun exposure, appropriate dietary intake, and the use of effective supplements. Factors such as the form of vitamin D, fat intake, and the use of specific analogues can significantly influence absorption rates. Further research is needed to fully understand the genetic and physiological factors affecting vitamin D3 bioavailability.
Sources and full results
Most relevant research papers on this topic
Stimulation of intestinal calcium absorption by orally administrated vitamin D3 compounds: a prospective open-label randomized trial in osteoporosis
Oral vitamin D3 analogues (ALF and ELD) stimulate intestinal calcium absorption in post-menopausal osteoporosis patients, suggesting they may directly stimulate intestinal vitamin D receptors.
RCT
Rigorous JournalSunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease.
Sunlight and vitamin D are essential for bone health, autoimmune diseases, cancers, and cardiovascular disease prevention.
Highly CitedVitamin D Bioavailability: State of the Art
Ergocalciferol and 25-hydroxyvitamin D are both absorbed similarly, but 25-hydroxyvitamin D is better absorbed, and aging has no effect on vitamin D absorption efficiency.
Literature ReviewHighly CitedIntestinal absorption of vitamin D: a systematic review
Vitamin D absorption involves passive diffusion and membrane carriers, with some data suggesting that fat consumption with vitamin D improves absorption.
Systematic ReviewHighly CitedThe effect of vitamin D on calcium absorption in older women.
High doses of vitamin D3 do not significantly increase calcium absorption in postmenopausal women, and the same amount could be obtained from half a glass of milk or 100 mg elemental calcium.
RCTOverview of general physiologic features and functions of vitamin D.
Vitamin D3 plays a crucial role in calcium absorption, phosphate absorption, bone mobilization, and kidney reabsorption, with new selective analogs for therapy emerging.
Highly CitedSunlight and Vitamin D
A three-part strategy involving food fortification, sensible sun exposure, and vitamin D supplementation can prevent global vitamin D deficiency and its negative health consequences.
Highly CitedA Randomized Trial of Vitamin D3 Supplementation in Children: Dose-Response Effects on Vitamin D Metabolites and Calcium Absorption
Vitamin D3 supplementation increases serum 25(OH)D levels but does not increase calcium absorption in healthy children at different latitudes.
RCT
Large Human TrialRigorous JournalHighly CitedNovel micellar system for Vitamin D3 oral delivery: Assessment of enteric absorption through a digestion-like in vitro model
A novel micellar liquid system significantly improves Vitamin D3 enteric bioaccessibility and enteric permeation rate compared to unformulated oil, enhancing its oral delivery.
In Vitro StudyMolecular Mechanisms of Vitamin D Action
Vitamin D action in cells depends on sufficient 1,25D ligand, VDR and RXR expression, and cell-specific programming of transcriptional responses to regulate specific genes, potentially delaying chronic aging disorders.
Rigorous JournalHighly Cited