A recent review in Nutrients talks about the benefits and safety of taking 2000 IU (50 µg) of vitamin D daily to prevent and treat vitamin D deficiency in adults.

Background: Not having enough vitamin D can lead to health problems, especially in the bones. The review suggests it might also help prevent diseases like cancer and diabetes. To check vitamin D levels, they look at a substance called 25-hydroxyvitamin D (25(OH)D) in the blood. Low levels, seen in 5-18% and 24-49% of people, highlight the need to address vitamin D deficiency globally.

Dosage and Safety: Taking 50µg daily can increase vitamin D levels, but there are safety concerns, especially for those at higher levels. However, the focus should be on reaching levels that prevent health issues rather than just worrying about safety.

Current Guidelines: Guidelines suggest 400-800 IU daily, but some may need more, like 2008-2672 IUs, to achieve specific vitamin D levels.

Target Levels: To improve health outcomes, especially for diabetes and cancer, it’s suggested to aim for 75 nmol/L or more. Optimal levels may vary depending on the study and population.

Considerations for Different People: Obese individuals, those with higher BMI, and certain conditions may need more vitamin D. Factors like inflammatory bowel disease or certain medications can impact vitamin D levels.

Safety from Trials: Recent trials show that 2000 IU daily is safe for adults for over five years. Meta-analyses reveal no increased risks for certain dose ranges.

Conclusions: Taking lower doses might not be enough, and daily supplements work better than occasional large doses. Personalized approaches, ranging from 800-2000 IUs, are recommended based on individual needs.

Review’s Recommendation: The review suggests taking 2000 IU (50 µg) of vitamin D daily to maintain good vitamin D levels in the majority of adults, with minimal safety concerns, even for those with enough vitamin D initially. This could be a helpful solution for vitamin D deficiency in adults.


McCullough PJ, Lehrer DS, Amend J. Daily oral dosing of vitamin D3 using 5000 TO 50,000 international units a day in long-term hospitalized patients: Insights from a seven year experience. J Steroid Biochem Mol Biol. 2019 May;189:228-239. doi: 10.1016/j.jsbmb.2018.12.010. Epub 2019 Jan 4. PMID: 30611908.

Pludowski, P., Grant, W. B., Karras, S. N., Zittermann, A., & Pilz, S. (2024). Vitamin D Supplementation: A Review of the Evidence Arguing for a Daily Dose of 2000 International Units (50 µg) of Vitamin D for Adults in the General Population. Nutrients16(3), 391. doihttps://doi.org/10.3390/nu16030391https://www.mdpi.com/2072-6643/16/3/391