How much Vitamin D (D2: Ergocalciferol, and D3: Cholecalciferol) should I take daily?
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
Daily Vitamin D Intake: Ergocalciferol (D2) and Cholecalciferol (D3)
Introduction to Vitamin D Supplementation
Vitamin D is essential for maintaining healthy bones and supporting immune function. It exists in two primary forms: ergocalciferol (D2) and cholecalciferol (D3). Both forms are used in supplements, but their efficacy and optimal dosing can vary.
Efficacy of Vitamin D2 vs. D3
Comparative Effectiveness
Research indicates that cholecalciferol (D3) is generally more effective than ergocalciferol (D2) in raising and maintaining serum 25-hydroxyvitamin D [25(OH)D] levels. A systematic review and meta-analysis found that D3 is superior in improving vitamin D status and reducing parathyroid hormone (PTH) levels across various dosages and demographics. Another study confirmed that D3 increases total 25(OH)D more effectively than D2, which can even lead to a decrease in 25(OH)D3 levels when supplemented with D2.
Dosage and Administration
Different studies have explored various dosing regimens for both forms of vitamin D. For instance, a study involving older adults showed that both daily (1,600 IU) and monthly (50,000 IU) doses of D2 and D3 were effective, but D3 had a slight edge in increasing serum 25(OH)D levels. Another study demonstrated that a high-dose regimen of D3 (50,000 IU twice weekly) was the most effective in rapidly achieving and maintaining adequate vitamin D levels.
Recommended Daily Intake
General Recommendations
For most adults, a daily intake of 2,000 to 3,000 IU of D3 is effective in maintaining adequate vitamin D levels without causing toxicity. This dosage is particularly recommended for individuals with low baseline vitamin D levels or those at risk of deficiency.
High-Dose Interventions
In cases of severe deficiency, higher doses may be necessary. A single large dose of 300,000 IU of D3 has been shown to significantly improve vitamin D status for up to three months. However, doses above 500,000 IU should be used cautiously to avoid adverse effects.
Special Populations
For individuals with obesity, higher doses of D3 may be required to achieve adequate serum 25(OH)D levels. A study on obese infertile men found that an initial bolus of 300,000 IU followed by daily supplementation of 1,400 IU was effective in reaching sufficient vitamin D levels.
Safety and Tolerable Upper Intake Levels
The European Food Safety Authority (EFSA) has established a tolerable upper intake level (UL) of 100 µg (4,000 IU) per day for adults, including pregnant and lactating women, to prevent hypercalcemia and other adverse effects. For children aged 1-10 years, the UL is set at 50 µg (2,000 IU) per day.
Conclusion
Cholecalciferol (D3) is generally more effective than ergocalciferol (D2) in improving and maintaining vitamin D levels. For most adults, a daily intake of 2,000 to 3,000 IU of D3 is recommended. In cases of severe deficiency or for individuals with obesity, higher doses may be necessary, but should be administered with caution to avoid toxicity. Always consult with a healthcare provider before starting any new supplementation regimen.
Sources and full results
Most relevant research papers on this topic
Evaluation of ergocalciferol or cholecalciferol dosing, 1,600 IU daily or 50,000 IU monthly in older adults.
Relative Efficacy of Vitamin D2 and Vitamin D3 in Improving Vitamin D Status: Systematic Review and Meta-Analysis
A PROSPECTIVE STUDY OF COMMONLY UTILIZED REGIMENS OF VITAMIN D REPLACEMENT AND MAINTENANCE THERAPY IN ADULTS.
Large, single-dose, oral vitamin D supplementation in adult populations: a systematic review.
Scientific opinion on the tolerable upper intake level for vitamin D, including the derivation of a conversion factor for calcidiol monohydrate
Bioavailability of vitamin D(2) and D(3) in healthy volunteers, a randomized placebo-controlled trial.
Differential effects of vitamin D2 and D3 supplements on 25-hydroxyvitamin D level are dose, sex, and time dependent: a randomized controlled trial
Short and long-term variations in serum calciotropic hormones after a single very large dose of ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) in the elderly.
Effects of a 10-day course of a high dose calciferol versus a single mega dose of ergocalciferol in correcting vitamin D deficiency
High-dose cholecalciferol supplementation to obese infertile men is sufficient to reach adequate vitamin D status.
Try another search
What are the implications of wearable health technology?
The implications of autonomous weapon systems on warfare ethics and international law.
most closely related to dinosaurs
what is sleep
What are the strategies for addressing the challenges of antibiotic resistance in medical treatment?
How do you increase local voter turnout?