Vitamin D is essential for life. A deficiency can have adverse health effects, which is why supplementation is often recommended. But as an English case study now shows: Too much vitamin D in the body can also be dangerous.
Vitamin D is essential for healthy bones and a strong immune system. A deficiency is associated with both osteoporosis and cancer or dementia (reported FITBOOK).1.2 According to studies, the risk of contracting Corona infection and becoming seriously ill is influenced, among other things, by the vitamin D status.3 No wonder, therefore, that vitamin D in the form of dietary supplements is becoming more and more popular. But when you take it, it is important to pay attention to the correct amount. Because, as a current description of the case by doctors in BMJ Case Reports shows, a vitamin D overdose is not something to mess with.4
Case description: the man suffers from an overdose of vitamin D
The English case described concerns a middle-aged man who was hospitalized by his family doctor with severe symptoms. On the advice of a nutritionist, the patient had started an intensive vitamin supplementation program. A month later, his health problems began, which had lasted for three months when he arrived at the clinic.
It turned out that the affected person had taken more than 20 vitamins. These included vitamins C, K2, B6 (pyridoxine), B9 (folic acid) and B2 (riboflavin). The man took a particularly excessive dose of vitamin D, or 50,000 IU or IE (international unit) three times a day, for a total of 150,000 and therefore “375 times more than the recommended daily dose”, as Dr. Alumin Alkundi, of William Harvey Hospital in East Kent, England, attending physician and co-author of the case report, said when asked by CNN.5 When the symptoms appeared, the patient had stopped the dietary supplements, but two months later they had not disappeared from the system.
How does hypervitaminosis D manifest?
The first blood tests by the family doctor showed that the man had very high levels of calcium and magnesium. Vitamin D levels were seven times those considered healthy.
As a result, the patient had developed acute kidney injury. And other alarming health conditions emerged, including tuberculosis, a tumor in the inner ear (left vestibular schwannoma) that caused deafness in that ear, fluid buildup in the brain (hydrocephalus), bacterial meningitis, and chronic sinusitis (inflammation sinuses).
Known symptoms of vitamin D overdose
As doctors explain in their report, hypervitaminosis D is mainly caused by an excess of calcium in the blood and can be as varied as it is severe. Known symptoms include:
Although cases of hypervitaminosis D appear to be on the rise, doctors point out that relatively little is known about it. Therefore, further complaints, including those of a long-term nature, cannot be ruled out.
Also interesting: Vitamin D – all information on function, requirement and dietary supplements
How is hypervitaminosis D treated?
In the case of the English patient, eight days of hospital treatment followed. He was given intravenous fluids to flush his system and bisphosphonates. These are drugs that are usually used to strengthen bones or to lower excessive calcium levels in the blood.
Two months after he was discharged from the hospital, the man’s calcium levels had returned to normal, but his vitamin D levels were still significantly elevated. “This case once again highlights the potential toxicity of dietary supplements – which are widely recognized as safe – when taken in dangerous quantities or in dangerous combinations,” the report said.
What is the recommended dosage for vitamin D?
According to the German Society for Nutrition (DGE), there is a vitamin D deficiency when the concentration of 25-hydroxyvitamin D (25 (OH) D) in the blood is below the desired value of 50 nmol / l. About 60 percent of people in Germany are affected. As the Robert Koch Institute points out, the body can contribute 80 to 90 percent of nutrient supply through its own synthesis if it is spent regularly outdoors. 10 to 20 percent can be ingested through food (e.g. fish, eggs, mushrooms). The DGE states that 20 µg of vitamin D should be taken every day, provided that the body’s synthesis is disturbed. This can be done through the skin and in the form of dietary supplements.6.7
In view of the dangers of a vitamin D overdose, you should first have your vitamin levels checked by a doctor. In the event of a deficiency, one can then decide to what extent spending more time outdoors and eating can help – or whether, and if so, in what dosage, a supplemental preparation makes sense.
- 1. Niedermeier, T., Gredner, T., Kuznia, S. et al. (2021). Supplementing vitamin D in the older adult population in Germany has the cost-saving potential of preventing nearly 30,000 cancer deaths per year. Molecular Oncology.
- 2. Navale, SS, Mulugeta, A., Zhou, A., et al. (2022): Vitamin D and Brain Health: An Observational and Mendelian Randomization Study. The American Journal of Clinical Nutrition.
- 3. Dror, AA, Morozov, N., Daoud, A. et al. (2022) Pre-infection 25-hydroxyvitamin D3 levels and association with COVID-19 disease severity. PLO ONE
- 4. Alkundi, A., Momoh, R., Musa, A., Nwafor, N. (2022). Vitamin D poisoning and severe hypercalcemia that complicate the abuse of dietary supplements. BMJ Case Reports.
- 5. LaMotte, S. As an increasingly popular supplement brought a man to the hospital. CNN. (aufgerufen am 7.7.2022)
- 6. German Society of Nutrition (DGE). New reference values for vitamin D. (accessed 07/07/2022)
- 7. Robert Koch Institute. Robert Koch Institute Answers to Frequently Asked Questions About Vitamin D. (Accessed July 7, 2022)