Canonical ingredient
Vitamin D2 (ergocalciferol)
vitamin formNot medically reviewed
- Parent supplement
- Vitamin D
- Direct source
- Vitamin D
- Source revision
- June 27, 2025
Ingredient evidence comparison · non-production preview
Compare ingredient evidence without rankings.
See what each frozen source explicitly supports, where evidence differs, and which questions remain unavailable.
Selected concepts
Two independent ingredient records
Canonical ingredient
Magnesium oxide
mineral compoundNot medically reviewed
- Parent supplement
- Magnesium
- Direct source
- Magnesium
- Source revision
- January 6, 2026
Inspect structural observations
- The selected ingredients have different parent supplement relationships. This is an identity distinction, not a clinical ranking.
- Direct evidence for “Identity and what it is” is available for Vitamin D2 (ergocalciferol) and unavailable for Magnesium oxide.
- Direct evidence for “Common uses” is unavailable for both selected ingredients.
- Direct evidence for “Biological role” is unavailable for both selected ingredients.
- Direct evidence for “What evidence has studied” is unavailable for both selected ingredients.
- Direct evidence for “Potential benefits studied” is unavailable for both selected ingredients.
- Direct evidence for “Safety considerations” is unavailable for both selected ingredients.
- Direct evidence for “Side effects” is unavailable for both selected ingredients.
- Direct evidence for “Medication interactions” is unavailable for both selected ingredients.
- Direct evidence for “Supplement interactions” is unavailable for both selected ingredients.
- Direct evidence for “Food interactions” is unavailable for both selected ingredients.
- Direct evidence for “Intake and dose reference information” is unavailable for both selected ingredients.
- Direct evidence for “Populations needing caution” is unavailable for both selected ingredients.
- Direct evidence for “Pregnancy and lactation” is unavailable for both selected ingredients.
- Direct evidence for “Laboratory and test considerations” is unavailable for both selected ingredients.
- Direct evidence for “Regulatory status” is unavailable for both selected ingredients.
- Direct evidence for “Evidence limitations” is unavailable for both selected ingredients.
Aligned evidence topics
Availability stays specific to each ingredient
Identity and what it is
available only for aA frozen NIH ODS source explicitly identifies this ingredient or form. Source wording is preserved without creating a new conclusion.
Structural characterization
Evidence profile
- Evidence source
- NIH ODS evidence synthesis
- Linked references
- 1 identified
- Human evidence
- Human evidence not identified in the frozen metadata
- Randomized trials
- Randomized trials not identified in the frozen metadata
- Reviews and meta-analyses
- Systematic review or meta-analysis identified
- Evidence recency
- 2018–2018
- Source-described consistency
- Not characterized in these source blocks
- MEDucated evidence rating
- Not assigned
Reference counts describe frozen source associations; a larger count does not establish stronger evidence.
Inspect technical evidence details
Evidence types identified
- Systematic review1
Source-described limitations
No explicit limitation phrase was identified in these imported source blocks.
Classified references
Silva MC, Furlanetto TW. Intestinal absorption of vitamin D: A systematic review. Nutr Rev 2018;76:60-76. [PubMed abstract]
Systematic review · Population basis: unknown · Directness: not assessed
Read source wording for Vitamin D2 (ergocalciferol)
In foods and dietary supplements, vitamin D has two main forms, D2 (ergocalciferol) and D3 (cholecalciferol), that differ chemically only in their side-chain structures. Both forms are well absorbed in the small intestine. Absorption occurs by simple passive diffusion and by a mechanism that involves intestinal membrane carrier proteins [4]. The concurrent presence of fat in the gut enhances vitamin D absorption, but some vitamin D is absorbed even without dietary fat. Neither aging nor obesity alters vitamin D absorption from the gut [4].
Where did MEDucated get this?
Vitamin D
- Publisher
- NIH Office of Dietary Supplements
- Revision
- June 27, 2025
- Source fingerprint
- 825b1a553a4a177e2d87fc412b0b4b21daa72ca92f4334a0096bc0dfa7f70a3c
- Source blocks
- ingredient-block:vitamin-d2-ergocalciferol:ods-block:vitamin-d-health-professional:introduction:5
Source attribution does not imply NIH or ODS endorsement of MEDucated.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Common uses
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Biological role
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
What evidence has studied
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Potential benefits studied
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Safety considerations
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Side effects
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Medication interactions
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Supplement interactions
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Food interactions
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Forms and chemical variants
available for bothA frozen NIH ODS source explicitly identifies this ingredient or form. Source wording is preserved without creating a new conclusion.
Structural characterization
Evidence profile
- Evidence source
- NIH ODS evidence synthesis
- Linked references
- 8 identified
- Human evidence
- Human evidence identified
- Randomized trials
- Randomized trial identified
- Reviews and meta-analyses
- Systematic review or meta-analysis identified
- Evidence recency
- 2007–2020
- Source-described consistency
- Not characterized in these source blocks
- MEDucated evidence rating
- Not assigned
Reference counts describe frozen source associations; a larger count does not establish stronger evidence.
Inspect technical evidence details
Evidence types identified
- Systematic review1
- Study type could not be determined4
- Meta-analysis1
- Randomized controlled trial2
Source-described limitations
No explicit limitation phrase was identified in these imported source blocks.
Classified references
Silva MC, Furlanetto TW. Intestinal absorption of vitamin D: A systematic review. Nutr Rev 2018;76:60-76. [PubMed abstract]
Systematic review · Population basis: unknown · Directness: not assessedHolick MF. Vitamin D deficiency. N Engl J Med 2007;357:266-81. [PubMed abstract]
Study type could not be determined · Population basis: unknown · Directness: not assessedHirsch AL. Industrial Aspects of Vitamin D. In: Feldman D, Pike JW, Adams JS, eds. Vitamin D. 3rd ed. Academic Press; 2011:73-93.
Study type could not be determined · Population basis: unknown · Directness: not assessedNational Institutes of Health. Dietary Supplement Label Database. 2020.
Study type could not be determined · Population basis: unknown · Directness: not assessedTripkovic L, Lambert H, Hart K, Smith CP, Bucca G, Penson S, et al. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: A systematic review and meta-analysis. Am J Clin Nutr 2012;95:1357-64. [PubMed abstract]
Meta-analysis · Population basis: unknown · Directness: not assessedLehmann U, Hirche F, Stangl GI, Hinz K, Westphal S, Dierkes J. Bioavailability of vitamin D2 and D3 in healthy volunteers, a randomised placebo-controlled trial. J Clin Endocrin Metab 2013;98:4339-45. [PubMed abstract]
Randomized controlled trial · Population basis: human · Directness: not assessedLogan VF, Gray AR, Peddie MC, Harper MJ, Houghton LA. Long-term vitamin D3 supplementation is more effective than vitamin D2 in maintaining serum 25-hydroxyvitamin D status over the winter months. Br J Nutr 2013;109:1082-8. [PubMed abstract]
Study type could not be determined · Population basis: unknown · Directness: not assessedTripkovic L, Wilson LR, Hart K, Johnsen S, de Lusignan S, Smith CP, et al. Daily supplementation with 15 µg vitamin D2 compared with vitamin D3 to increase wintertime 25-hydroxyvitamin D status in healthy South Asian and white European women: A 12-wk randomized, placebo-controlled food-fortification trial. Am J Clin Nutr 2017;106:481-90. [PubMed abstract]
Randomized controlled trial · Population basis: human · Directness: not assessed
Read source wording for Vitamin D2 (ergocalciferol)
Vitamin D is present in dietary supplements as either vitamin D2 or vitamin D3. Both can raise the serum level of 25(OH)D. However, research shows that vitamin D3 increases serum 25(OH)D levels to a greater extent than vitamin D2 and can maintain those higher levels for longer periods of time.
Dietary supplements can contain vitamins D2 or D3. Vitamin D2 is manufactured using UV irradiation of ergosterol in yeast, and vitamin D3 is typically produced with irradiation of 7-dehydrocholesterol from lanolin obtained from the wool of sheep [13,31]. An animal-free version of vitamin D3 sourced from lichen is also available [32]. People who avoid all animal-sourced products can contact dietary supplement manufacturers to ask about their sourcing and processing techniques.
Both vitamins D2 and D3 raise serum 25(OH)D levels, and they seem to have equivalent ability to cure rickets [4]. In addition, most steps in the metabolism and actions of vitamins D2 and D3 are identical. However, most evidence indicates that vitamin D3 increases serum 25(OH)D levels to a greater extent and maintains these higher levels longer than vitamin D2, even though both forms are well absorbed in the gut [33-36].
Where did MEDucated get this?
Vitamin D
- Publisher
- NIH Office of Dietary Supplements
- Revision
- June 27, 2025
- Source fingerprint
- 825b1a553a4a177e2d87fc412b0b4b21daa72ca92f4334a0096bc0dfa7f70a3c
- Source blocks
- ingredient-block:vitamin-d2-ergocalciferol:ods-block:vitamin-d-health-professional:dietary-supplements:1, ingredient-block:vitamin-d2-ergocalciferol:ods-block:vitamin-d-health-professional:dietary-supplements:2, ingredient-block:vitamin-d2-ergocalciferol:ods-block:vitamin-d-health-professional:dietary-supplements:3
Source attribution does not imply NIH or ODS endorsement of MEDucated.
A frozen NIH ODS source explicitly identifies this ingredient or form. Source wording is preserved without creating a new conclusion.
Structural characterization
Evidence profile
- Evidence source
- NIH ODS evidence synthesis
- Linked references
- 8 identified
- Human evidence
- Human evidence identified
- Randomized trials
- Randomized trial identified
- Reviews and meta-analyses
- Systematic reviews or meta-analyses not identified in the frozen metadata
- Evidence recency
- 1990–2012
- Source-described consistency
- Not characterized in these source blocks
- MEDucated evidence rating
- Not assigned
Reference counts describe frozen source associations; a larger count does not establish stronger evidence.
Inspect technical evidence details
Evidence types identified
- Study type could not be determined6
- Pharmacokinetic study1
- Randomized controlled trial1
Source-described limitations
- ODS describes a small study base
The absorption of magnesium from different kinds of magnesium supplements varies. Forms of magnesium that dissolve well in liquid are more completely absorbed in the gut than less soluble forms [2,12]. Small studies have found that magnesium in the aspartate, citrate, lactate, and chloride forms is absorbed more completely and is more bioavailable than magnesium oxide and magnesium sulfate [12-16]. One study found that very high doses of zinc from supplements (142 mg/day) can interfere with magnesium absorption and disrupt the magnesium balance in the body [17].
Classified references
Rude RK. Magnesium. In: Coates PM, Betz JM, Blackman MR, Cragg GM, Levine M, Moss J, White JD, eds. Encyclopedia of Dietary Supplements. 2nd ed. New York, NY: Informa Healthcare; 2010:527-37.
Study type could not be determined · Population basis: unknown · Directness: not assessedRude RK. Magnesium. In: Ross AC, Caballero B, Cousins RJ, Tucker KL, Ziegler TR, eds. Modern Nutrition in Health and Disease. 11th ed. Baltimore, Mass: Lippincott Williams & Wilkins; 2012:159-75.
Study type could not be determined · Population basis: unknown · Directness: not assessedRanade VV, Somberg JC. Bioavailability and pharmacokinetics of magnesium after administration of magnesium salts to humans. Am J Ther 2001;8:345-57. [PubMed abstract]
Pharmacokinetic study · Population basis: human · Directness: not assessedFiroz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnes Res 2001;14:257-62. [PubMed abstract]
Study type could not be determined · Population basis: unknown · Directness: not assessedMühlbauer B, Schwenk M, Coram WM, Antonin KH, Etienne P, Bieck PR, Douglas FL. Magnesium-L-aspartate-HCl and magnesium-oxide: bioavailability in healthy volunteers. Eur J Clin Pharmacol 1991;40:437-8. [PubMed abstract]
Study type could not be determined · Population basis: human · Directness: not assessedLindberg JS, Zobitz MM, Poindexter JR, Pak CY. Magnesium bioavailability from magnesium citrate and magnesium oxide. J Am Coll Nutr 1990;9:48-55. [PubMed abstract]
Study type could not be determined · Population basis: unknown · Directness: not assessedWalker AF, Marakis G, Christie S, Byng M. Mg citrate found more bioavailable than other Mg preparations in a randomized, double-blind study. Mag Res 2003;16:183-91. [PubMed abstract]
Randomized controlled trial · Population basis: unknown · Directness: not assessedSpencer H, Norris C, Williams D. Inhibitory effects of zinc on magnesium balance and magnesium absorption in man. J Am Coll Nutr 1994;13:479-84. [PubMed abstract]
Study type could not be determined · Population basis: unknown · Directness: not assessed
Read source wording for Magnesium oxide
Supplements can contain a variety of different forms of magnesium, and the absorption of these forms varies. In general, forms of magnesium that dissolve well in liquid have higher absorption than other forms, and the aspartate, citrate, lactate, and chloride forms of magnesium tend to have higher bioavailability than magnesium oxide and magnesium sulfate.
Magnesium supplements are available in a variety of forms, including magnesium oxide, citrate, and chloride [2,3]. The Supplement Facts panel on a dietary supplement label declares the amount of elemental magnesium in the product, not the weight of the entire magnesium-containing compound.
The absorption of magnesium from different kinds of magnesium supplements varies. Forms of magnesium that dissolve well in liquid are more completely absorbed in the gut than less soluble forms [2,12]. Small studies have found that magnesium in the aspartate, citrate, lactate, and chloride forms is absorbed more completely and is more bioavailable than magnesium oxide and magnesium sulfate [12-16]. One study found that very high doses of zinc from supplements (142 mg/day) can interfere with magnesium absorption and disrupt the magnesium balance in the body [17].
Where did MEDucated get this?
Magnesium
- Publisher
- NIH Office of Dietary Supplements
- Revision
- January 6, 2026
- Source fingerprint
- 0f84702092574ff8a3b3fe01ab3a977c6a76d37e18b758e3e94b6d3ca55c3d59
- Source blocks
- ingredient-block:magnesium-oxide:ods-block:magnesium-health-professional:dietary-supplements:1, ingredient-block:magnesium-oxide:ods-block:magnesium-health-professional:dietary-supplements:2, ingredient-block:magnesium-oxide:ods-block:magnesium-health-professional:dietary-supplements:3
Source attribution does not imply NIH or ODS endorsement of MEDucated.
Intake and dose reference information
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Populations needing caution
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Pregnancy and lactation
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Laboratory and test considerations
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Regulatory status
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Evidence limitations
unavailable for bothDirect source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.
Direct source evidence for this ingredient topic is not yet available in MEDucated.
No direct source block is attached to this ingredient topic.