## Vitamin and mineral union [Calcium](https://ul.orna.me/KOge/librarybiomarker?id=127) in the body is regulated by vitamin D and parathormone. Lack of parathormone is a rare phenomenon, but a lack of [vitamin D](https://ul.orna.me/KOge/librarybiomarker?id=187) affects a huge number of people on the planet. Let’s look at how vitamin D and calcium levels in the body are related. It is impossible to overestimate the impact of vitamin D on the body. It is a prohormone that is produced in the human body through the sunlight that reaches the skin. It has a positive effect on the immune system, reduces symptoms of chronic fatigue, and reduces the risk of several cancers, diabetes, multiple sclerosis, cardiovascular disease, and tuberculosis. Vitamin D is responsible for the absorption of calcium and phosphorus and the formation of skeletal bones. Since calcium is involved in several million different processes, from neuromuscular transmission to milk secretion, vitamin D plays an indirect yet significant role in these processes too. > Normal adult calcium content is 8.6–10.3 mg/dl, and normal vitamin D content is 20–40 mg/dl. ## The right combination is the key to health One of the main functions of vitamin D is to keep bones healthy and strong for as long as possible. This is achieved through a perfect alliance with calcium, which is the prohormone responsible for its absorption. If your vitamin D levels are within the normal range but your calcium levels are not, it means that the vitamin D is not enough for your body to absorb calcium normally. In this case, your doctor will choose the right combination of supplements to increase your vitamin D and calcium levels and reduce your risk of osteoporosis and different kinds of fractures. That is why it is best to take these tests in tandem.