Why would you use Vitamin D2 (ergocalciferol)?

From the Guidelines

Vitamin D2 (ergocalciferol) should be used to treat vitamin D deficiency, particularly in patients with serum 25(OH) D levels below 30 ng/mL, as it is a viable option for raising 25(OH) D concentrations, especially for those with strict vegetarian or vegan diets. When considering the use of Vitamin D2, it is essential to evaluate the patient's serum 25(OH) D levels, as this is the best indicator of vitamin D status 1. According to the NCCN task force report, a common regimen for patients with serum 25(OH) D levels below 30 ng/mL is prescription vitamin D (ergocalciferol) 50,000 IU weekly for 8 weeks, followed by a recheck of the serum 25(OH) D level, with subsequent dosing based on the results 1. Some key points to consider when using Vitamin D2 include:

• The goal of supplementation is to bring serum 25(OH) D levels to 30 ng/ml (75 nmol/L) or higher for bone health 1
• Vitamin D2 is metabolized differently than vitamin D3, but no difference in maintaining 25(OH) D levels was found when daily dosing was studied 1
• Vitamin D toxicity is uncommon but may occur with daily doses of more than 50,000 IU per day that produce 25(OH) D levels larger than 150 ng/mL 1
• Current expert opinion recommends 800 to 1000 IU of vitamin D daily for adults older than age 50, and 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

From the Research

Uses of Vitamin D2 (Ergocalciferol)

• Vitamin D2 (ergocalciferol) is used to treat vitamin D deficiency, which can cause symptoms such as symmetric low back pain, proximal muscle weakness, muscle aches, and throbbing bone pain 2
• It is also used to prevent vitamin D deficiency in individuals who are at risk, such as those with limited sun exposure or certain medical conditions 2
• Vitamin D2 can be administered orally at a dose of 50,000 IU per week for eight weeks to treat deficiency, and then maintained with cholecalciferol (vitamin D3) at 800 to 1,000 IU per day 2

Treatment Regimens

• A study found that treating vitamin D deficiency with 50,000 IU of vitamin D2 per week for 8-12 weeks was effective in increasing vitamin D levels, with success rates of 82%, 75%, and 71% after 8,10, and 12 weeks of therapy, respectively 3
• Another study compared the effectiveness of vitamin D2 and vitamin D3 replacement therapy, and found that vitamin D3 was superior to vitamin D2 in restoring severe vitamin D deficiency, with a greater increase in serum vitamin D levels 4
• A study on the tolerability and biochemical effects of high-dose bolus vitamin D2 and D3 supplementation found that both formulations were well tolerated, but vitamin D3 had greater potency than equimolar vitamin D2, with a higher and more sustained serum 25(OH)D response 5

Efficacy and Safety

• A retrospective analysis of 306 patients prescribed ergocalciferol (vitamin D2) for correction of vitamin D insufficiency found that regimens with >600,000 IU of ergocalciferol given for a mean of 60 +/- 40 days achieved sufficiency in 64% of cases, without vitamin D toxicity 6
• The study also found that vitamin D2 was effective in increasing serum 25-OHD levels, but the efficacy varied depending on the regimen used, with some regimens achieving sufficiency in only 38-42% of cases 6