While we all need vitamin D, it is possible to have too much. You cannot get too much vitamin D from sun exposure (although remember to bring your sun cream as prolonged exposure can increase the risk of skin cancer) but you can take too much vitamin D from overdoing the supplements.
Too much vitamin D in the blood, often referred to as vitamin D toxicity, and medically as ‘hypervitaminosis D’, is rare, but can happen if you take too many supplements that equate to more than 100μg.4,9
Your body can only absorb so much vitamin D at a time, and it’s very difficult to get more than 10% of your daily recommended intake through food. So, it’s almost impossible to get too much vitamin D from food sources alone.2,4,6,7
However, it’s easy to take too many vitamin D supplements, making this the most common cause of vitamin D toxicity.9
To avoid vitamin D toxicity, you shouldn’t take more than 100μg (4,000 IU) of vitamin D a day.4 This applies to all adults and children over 11 years old.4
Children aged one to 10 years shouldn’t have more than 50μg (2,000 IU) a day. Babies under a year old shouldn’t have more than 25μg (1,000 IU) a day.4