Vitamin D deficiency is common in Parkinson disease (PD). In fact, as previously discussed in MPDN, this vitamin is involved in dopamine production. Generally speaking, we also need adequate stores for the health of our bones, heart, and metabolism. Vitamin D is also involved in innate immunity, a part of our immune system that includes physical barriers (for example, skin), compounds found in the blood, and certain white blood cells that directly attack foreign cells and substances in the body, so-called antigens. Vitamin D can lower inflammation and help fight certain viruses. It is also known that vitamin D deficiency is associated with respiratory infections. Normalizing vitamin D levels seems to help prevent these infections. A meta-analysis (a comparison of multiple studies) of 25 randomized clinical trials of vitamin D supplementation found that among the nearly 11,000 patients supplementation correlated with 12% reduced risk of respiratory tract infections. In people with severe vitamin D deficiency at baseline adding vitamin D supplementation was associated with a 70% lower risk of respiratory infection.
Now, there is data that vitamin D deficiency is associated with COVID-19. And, severe outcome was eight times more likely among COVID-19 patients with vitamin D deficiency compared to those with normal levels in a report from three Asian hospitals. It should be noted that generally, people with severe vitamin D deficiency tend to have underlying have underlying health issues also. Nonetheless, vitamin D levels may play a role with severe outcomes of COVID-19, such as the “cytokine storm” that usually precipitates critical illness in this disease.
The problem is that many people with PD are not getting out to exercise or get a little sunshine. This is a bad combination. Low exercise is associated with poor outcomes in PD. Not getting appropriate sunshine (and therefore the UV light needed to convert vitamin D to its active form), is associated with vitamin D deficiency. So please, get a few minutes of sunshine daily, eat foods that contain vitamin D, and if your vitamin D is low, please replace it with the direction of your doctor. Some authors have suggested vitamin D supplementation should be universal with PD patients, at least during the time of COVID-19. I would caution however, that you avoid vitamin D toxicity.
