How often should I take Vitamin D (Vitamin D) 10,000 International Units (IU)?

From the Guidelines

Vitamin D 10,000 IU should be taken once daily under medical supervision for short-term correction of severe vitamin D deficiency, but the most recent and highest quality study recommends daily doses of 8,000 IU/d orally or enterally for 4 weeks, or 50,000 IU/week for 4 weeks, then 4,000 IU/d or 50,000 IU twice per month for 2 months 1. This dose is well above the recommended daily allowance for most adults, which ranges from 600-800 IU per day. Taking 10,000 IU daily is usually prescribed for short-term correction of severe vitamin D deficiency rather than for long-term maintenance. When taking this high dose, you should have your vitamin D blood levels monitored regularly by your healthcare provider to prevent potential toxicity. Vitamin D is fat-soluble, meaning it's stored in your body's fat tissues and can accumulate to harmful levels if taken in excessive amounts over time. Common signs of vitamin D toxicity include nausea, vomiting, weakness, and kidney problems. For better absorption, take vitamin D supplements with a meal containing some fat. If you're currently taking this high dose without medical supervision, consult with your healthcare provider to determine if this is appropriate for your specific health needs. Some key points to consider:

• The recommended upper limit of vitamin D is 2,000 IU/day according to the Food and Nutrition Board, National Research Council, National Academy of Sciences 1.
• Dosage preparations of 10,000 IU of ergocalciferol have been given daily to patients with advanced CKD for periods longer than 1 year, with no evidence of vitamin D overload or renal toxicity 1.
• Vitamin D toxicity (hypercalcemia, hyperphosphatemia, and activation of bone resorption) 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.

From the Research

Vitamin D Dosage

• The ideal dosage of Vitamin D is still a topic of debate, with different studies suggesting varying amounts 2, 3, 4, 5.
• A study published in 2018 suggests that 400 IU of vitamin D per day is sufficient to prevent nutritional rickets or osteomalacia, while 800 IU per day may be necessary to prevent fractures and falls in elderly subjects 2.
• Another study from 2017 found that a single intramuscular injection of 600,000 IU of vitamin D3 can increase serum 25(OH)D levels for several weeks, but the safety of such high doses is still uncertain 3.
• A 2019 study reported that daily oral dosing of vitamin D3 using 5,000 to 50,000 IU per day in long-term hospitalized patients appeared to be safe, with no cases of vitamin D3-induced hypercalcemia or adverse events attributable to vitamin D3 supplementation 4.
• In terms of the specific dosage of 10,000 IU per day, the 2019 study found that this dose was well-tolerated and effective in increasing serum 25(OH)D levels in hospitalized patients 4.

Frequency of Vitamin D Supplementation

• The frequency of vitamin D supplementation is not explicitly stated in the provided studies, but it can be inferred that daily or weekly supplementation may be necessary to maintain adequate serum 25(OH)D levels 2, 3, 4.
• The 2019 study reported that daily oral dosing of vitamin D3 using 5,000 to 50,000 IU per day was effective in increasing serum 25(OH)D levels, suggesting that daily supplementation may be a viable option 4.
• However, more research is needed to determine the optimal frequency and dosage of vitamin D supplementation for different populations and health outcomes 5.