Vitamin D overdose: causes
A vitamin D overdose cannot occur naturally – i.e. neither through excessive exposure to the sun nor through eating plenty of foods that naturally contain a lot of vitamin D (such as fatty sea fish).
The situation is different if someone takes high doses of vitamin D supplements or medication and/or consumes large quantities of foods that have been enriched with vitamin D: Anyone who consumes more than 100 micrograms of vitamin D every day in this way risks side effects such as kidney stones. The reason for this is that the body does not simply excrete an excess of the fat-soluble vitamin D, but stores it in fat and muscle tissue.
In this way, excessive vitamin D intake can lead to both acute and chronic vitamin D overdose. Acute intoxication occurs when an excessively high dose of vitamin D (as a supplement) is taken in one go. Chronic vitamin D intoxication can develop if too much vitamin D is ingested over a long period of time (via supplements and/or vitamin D-enriched foods).
Vitamin D overdose: symptoms
A vitamin D overdose can trigger various health complaints, which are mainly due to an increased calcium level in the blood (hypercalcemia): The excess vitamin D causes the body to absorb an excessive amount of calcium from food and also to dissolve more calcium from the bones. Via this mechanism, an overdose of vitamin D can have the following effects, among others:
- Nausea and vomiting
- loss of appetite
- Extreme thirst (polydipsia)
- Increased urination (polyuria)
- Feeling of weakness
- headaches
- nervousness
- Kidney stones and kidney damage up to kidney failure
For this reason, you should not take vitamin D supplements on your own if you suspect a vitamin D deficiency or want to prevent one. It is better to go to the doctor and have your blood values determined. If you actually have too little vitamin D or are at an increased risk of such a deficiency, the doctor can prescribe a suitable preparation. He or she will determine the duration of intake and the dosage so that you do not have to worry about a vitamin D overdose.
