From the Guidelines
D3 is recommended over D2 for supplementation. Vitamin D3 (cholecalciferol) is the preferred form because it's more effective at raising and maintaining blood levels of vitamin D compared to vitamin D2 (ergocalciferol) 1. Typical supplementation doses range from 1,000-4,000 IU daily, though individual needs vary based on factors like sun exposure, age, and baseline levels.
Key Considerations
- D3 is approximately more potent at raising serum 25(OH)D concentrations and produces a more sustained elevation in these levels compared to D2 1.
- The body naturally produces D3 when skin is exposed to sunlight, making it the more physiologically natural form.
- For optimal absorption, take vitamin D3 supplements with a meal containing some fat, as vitamin D is fat-soluble.
- If you're deficient, higher doses may be needed initially under medical supervision.
Supplementation Guidelines
- Current expert opinion on supplementation for adults older than age 50 is 1200 mg of calcium (from all sources) and 800 to 1000 IU of vitamin D daily 1.
- The NCCN Bone Health in Cancer Care Task Force also recommends these ranges for younger patients at risk for cancer treatment–associated bone loss 1.
- A caveat to the vitamin D intake recommendation is that many patients need more than the recommended amount and should be repleted based on serum 25(OH) D level 1.
From the FDA Drug Label
Vitamin D3 50,000 IU is essential for absorption of calcium and necessary for healthy bones and a healthy immune system. The question D3 o D2 is not directly addressed in the provided drug label.
- The label only mentions Vitamin D3 and its importance for calcium absorption and healthy bones, but does not compare it to D2.
- There is no information in the label that supports a direct comparison between D3 and D2. The FDA drug label does not answer the question.
From the Research
Comparison of D3 and D2
- The choice between D3 (cholecalciferol) and D2 (ergocalciferol) for vitamin D supplementation depends on various factors, including the individual's health status and the desired outcome 2, 3.
- Cholecalciferol (D3) is considered the preferred form of vitamin D supplementation due to its greater efficacy in improving musculoskeletal health and its ability to guarantee an exact dosage in IU 2.
- Calcifediol (25OHD3), a form of vitamin D3, has been shown to be more potent than cholecalciferol, with a more rapid increase in serum 25OHD levels and a higher rate of intestinal absorption 3.
Efficacy and Safety
- Studies have demonstrated that vitamin D supplementation can improve musculoskeletal health, reduce the risk of fractures and falls, and have a positive effect on serum 25OHD levels 4, 5.
- The optimal dosage of vitamin D supplementation is still a topic of debate, with some studies suggesting that higher dosages (2,000-3,000 IU/day) may be necessary to achieve a relevant increase in 25OHD levels and normalization of parathyroid hormone (PTH) 5.
- The safety of vitamin D supplementation has been established, with few adverse effects reported at dosages up to 5,000 IU/day 4.
Clinical Guidelines
- Clinical guidelines recommend the use of cholecalciferol (D3) as the preferred form of vitamin D supplementation, with calcifediol (25OHD3) reserved for patients with liver failure or severe intestinal malabsorption syndromes 2.
- The decision to supplement with vitamin D should be based on individual patient needs and health status, with consideration given to the potential benefits and risks of supplementation 6.