While a healthy balance of vitamin D is essential to our health, too much vitamin D can be dangerous and cause illness. Excess vitamin D almost always occurs when supplements are overused. That's why it is important to consult a medical care provider when taking supplements. Here is how too much vitamin D can affect your body in a negative way.
Overconsumption of vitamin D is known as Hypervitaminosis D. It can lead to hardening of kidneys, heart, blood vessels and the lungs. It also causes the over-calcification of bones.
When levels of vitamin D are too high in your blood, toxicity occurs. You might experience dry mouth, headaches, loss of appetite, nausea, constipation, weight loss, confusion, a metallic taste in your mouth, vomiting and diarrhoea as a result.
High levels of vitamin D during pregnancy have an association with an increased risk of food allergy2 in a child within the first 2 years of life.
While exposure to sunlight is considered the main source of vitamin D and cannot cause vitamin D toxicity, it is important to limit your skin’s exposure to sunlight in order to reduce your risk of getting skin cancer.
Reference
2. February 2013. Maternal and newborn vitamin D status and its impact on food allergy development in the German LINA cohort study. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23253182. Accessed [25 October 2017]