Low levels of vitamin D can worsen the severity of multiple sclerosis (MS) and hasten the progression of the disease in its early stages, according to a new study at the Harvard School of Public Health (HSPH). The findings suggest that patients in the early stages of MS could stave off disease symptoms by taking vitamin D supplements.
“Because low vitamin D levels are common and can be easily and safely increased by oral supplementation, these findings may contribute to better outcomes for many MS patients,” said lead author Alberto Ascherio, a professor of epidemiology and nutrition at HSPH. The study is published online in JAMA Neurology.
MS is a chronic disease which attacks the body’s central nervous system. The three main characteristics of MS are the formation of lesions, inflammation, and the destruction of myelin, the membrane that protects nerves in the brain and spinal cord.
The most common form of the disease, relapsing-remitting multiple sclerosis, is characterized by episodes of worsening neurologic function followed by periods of remission. Symptoms may be mild or severe, ranging from numbness in the limbs to paralysis or loss of vision.
Previous studies have suggested there was an association between MS and vitamin D, but it was unclear if low levels of the vitamin were a predictor or a symptom of MS activity.
The new study looked at vitamin D levels in over 450 MS patients who developed the first symptoms of the disease. Their vitamin D levels were measured when they enrolled in the study and at regular intervals over a 24-month period—correlated with their disease symptoms and progression over a period of five years.
Researchers found that early-stage MS patients who had adequate levels of vitamin D had a 57% lower rate of new brain lesions, a 57% lower relapse rate, and a 25% lower increase in lesion volume than those with lower levels of vitamin D.
Loss in brain volume, which is an important predictor of disability, was also lower among patients with adequate vitamin D levels.
The results suggest that vitamin D has a strong protective effect on the disease process underlying MS, and underscore the importance of correcting vitamin D insufficiency, which is common in MS patients.
“The results of our study reveal a robust prognostic value of vitamin D levels measured early in the MS course and converge with previous epidemiological and biological evidence supporting a protective effect of vitamin D on the disease process underlying MS, and thus the importance of correcting vitamin D insufficiency, which affects about 50% of patients with MS in Europe39 and 20% in the United States.” wrote Ascherio.
“However, further investigations are needed to determine the optimal levels of vitamin D and whether results apply to different races or ethnicities.”
Funding for the study came from the National Institute of Neurological Diseases and Stroke and the National Multiple Sclerosis Society.
An estimated 400,000 Americans suffer from MS and more than two million people worldwide. There is no cure for MS; the only therapies currently available are ones that modify its symptoms.