Vitamin D supplementation in sarcoidosis only carries a slight risk, according to a new randomized controlled trial out of New Zealand.
Sarcoidosis is one of the few diseases where you need to be cautious in supplementing with vitamin D and cautious in getting good amounts of sun exposure. The reason is that in sarcoidosis, 4–11% of the patients develop high serum calcium (hypercalcemia). In any hypercalcemic condition, caution is needed in supplementing with vitamin D. While supplementation doesn’t need to be avoided, it should be closely monitored by a health care professional, to make sure that it doesn’t further increase serum calcium levels.
Sarcoidosis is particularly interesting in that the root cause of hypercalcemia is due to dysregulation of vitamin D. Macrophages in the body have no ability to control how much activated vitamin D [1,25(OH)2D] they produce, often producing too much activated vitamin D. In some cases, this leads to high serum calcium.
Despite this set of knowledge, there hasn’t been much clinical research on whether vitamin D supplementation can be tolerated in sarcoidosis. It’s not necessarily clear if vitamin D is to be avoided or used in low amounts in the condition, or if only those who suffer from hypercalcemia need to avoid supplementation.
Recently, researchers in New Zealand carried out a pilot randomized controlled trial, to see if a moderate and regular vitamin D supplement regimen would induce hypercalcemia or if it would be safe. They also wanted to know if vitamin D supplementation helped bone health, as there is also some concern that if people with sarcoidosis are avoiding vitamin D, their bones may become less dense or soft.
So the researchers enrolled 27 people with sarcoidosis into their trial. Thirteen patients received 50,000 IU of vitamin D (D3) once per week for four weeks and then once monthly for 11 more months. The other 14 participants received placebos pills.
The researchers monitored vitamin D and calcium levels regularly throughout the trial. They also measured bone mass density (BMD) of the lumbar spine, proximal femur and total body.
Here’s what they found:
- Mean baseline vitamin D levels were 14 ng/ml in the vitamin D group. At the end of trial, they were just over 30 ng/ml. In the placebo group, they hovered around 15 ng/ml for the duration of the trial.
- Of the 13 participants that were part of the vitamin D group, only one developed hypercalcemia. She therefore had to stop supplementation and drop out of the study.
- After one year, mean serum calcium did not increase in either the vitamin D or the placebo groups.
- Vitamin D supplementation didn’t have much effect on BMD. There was no statistically significant difference of BMD between vitamin D and placebo group.
Limitations of the study include small number of enrollees. However, this could pave the way for a larger trial.
Baseline vitamin D levels were as low as 5 ng/ml in one participant, a level that puts you at high risk for osteomalacia and infections. While this trial shows there is a slight risk in supplementing with vitamin D if you have sarcoidosis, the risks of maintaining very low vitamin D levels should also be evaluated. Here, they found no improvement in BMD over the course of the year. However, from here we need a vitamin D-sarcoidosis trial that measures multiple endpoints, including osteomalacia and infections. This current small trial has shown that there is only a slight risk of supplementing and that a larger trial could be carried out without putting a high percentage of participants at risk of hypercalcemia.
If you have sarcoidosis, be sure to work with your doctor if you want to supplement with vitamin D. Your doctor can track your calcium levels and determine if vitamin D supplementation is fine or whether it’s causing hypercalcemia.