Sarcoidosis
By Jens Allmer
Worldwide, this disease is relatively uncommon ranging from 1 to 80 cases per 100,000 people. The relationship to vitamin D is that in this condition large amounts of Calcitriol are produced bypassing the typical regulation controls.
Sarcoidosis is an inflammatory disease where granulomas (small clusters of immune cells) form in various organs, particularly the lungs and lymph nodes. In sarcoidosis, activated macrophages in these granulomas can convert Calcifediol to its active form, Calcitriol, independent of the body’s D3 regulation. This can lead to hypercalcemia (elevated calcium levels) and hypercalciuria (elevated calcium in urine). Hypercalcemia is an often cited reason for vitamin D toxicity. Clearly, in this case sarcoidosis is too blame and not vitamin D since the disease bypasses the regulatory mechanisms.
So in sarcoidosis Calcitriol is elevated and probably Calcifediol is low since the conversion is performed by the activated macrophages. With high Calcitriol, calcium is efficiently extracted from food. Even if the hormone Calcitonin which should lower Calcitriol levels is activated, the macrophages continue to convert the available Calcifediol to Calcitriol. In order to combat hypercalcemia under these condition, the following two steps seem critical.
- Reduce the calcium intake as much as possible.
- Do not supplement with large doses of Cholecalciferol. Rather supplement as much as would be needed on a daily basis.
- Check both Calcifediol and Calcitriol levels frequently so that the amount of supplementation can be adjusted correctly (Gianella et al., 2020).
Since Calcitriol is involved in a large number of processes in the body, it is essential for our health and well being. Therefore, we cannot just not have Calcitriol (the first proof of that was rickets disease). In sarcoidosis, we cannot rely on measuring Calcifediol levels as we would do in healthy individuals. This is because of the uncontrolled conversion of Calcifediol to Calcitriol in the activated macrophages. This means we need to ensure constant sufficient amounts of Cholecalciferol that is converted to Calcifediol and then Calcitriol but not too much to induce hypercalcemia. Calcium avoidance will make this process easier.
