Taking high doses of vitamin D can cause an increase in calcium in blood tests, a condition called hypercalcemia, even though the blood level of calcium may remain normal.
Vitamin D plays a critical role in regulating the levels of calcium in the body. It helps the body absorb calcium from the diet and also helps to redistribute calcium within the body. When vitamin D levels are low, the body will take calcium from the bones, when they are sufficient, the calcium is deposited into the bones.
When large doses of vitamin D are taken, the body may absorb more calcium from the diet than it needs, resulting in an increase in the level of calcium in the blood. This increase can be measured through a blood test. However, it is important to note that a high blood level of vitamin D alone does not necessarily cause hypercalcemia, it may be caused by other underlying issues such as bone and/or parathyroid disease, malignancy or certain medication.
It is important to consult a healthcare professional before taking high doses of vitamin D, and to have regular blood tests to monitor the levels of calcium and vitamin D in the body.