Yes. Vitamin D levels in the blood exceeding 375 nmol/L or 150 ng/mL are toxic, potentially causing side-effects such as loss of appetite, nausea, vomiting, muscle weakness, confusion, dehydration, excessive thirst, and kidney stones.[1] Extremely high blood levels of vitamin D can even be fatal.[2]
Since vitamin D production in the skin is self-limiting, it isn’t possible to get too much through sun exposure. However, vitamin D levels in the blood levels can reach toxic levels with chronic, high-level supplementation. Although ultra-high-level supplementation is universally considered to be toxic, there’s some debate on what constitutes the upper limit for safe, “moderate-level” supplementation. According to the National Institutes of Health Office of Dietary supplements, 4000 IU per day is the upper recommended limit for children 9 years old through adults. However, long-term supplementation up to 10,000 IU per day is not associated with any toxicity or adverse side effects.[3]
References
- ^Galior K, Grebe S, Singh RDevelopment of Vitamin D Toxicity from Overcorrection of Vitamin D Deficiency: A Review of Case Reports.Nutrients.(2018-Jul-24)
- ^Vitamin D Fact sheet for consumers. National Institutes of Health (NIH) Office of Dietary Supplements (ODS) updated 2022 Nov 8; cited 2023 May 24
- ^Michael J GladeA 21st century evaluation of the safety of oral vitamin DNutrition.(2012 Apr)