A new study by US researchers has found that Parkinson’s sufferers have insufficient levels of vitamin D compared to healthy people or Alzheimer’s patients. A team of researchers from the Emory University School of Medicine in Atlanta compared vitamin D levels in 100 Parkinson’s patients, 97 Alzheimer’s patients, and 99 healthy people of the same age.

The main purpose of the study was to determine whether Parkinson’s and Alzheimer’s may be linked to vitamin D deficiency.

More than half of patients with Parkinson’s had low levels of vitamin D, compared to 41% of the Alzheimer’s patients and 10% of the group of healthy people. The average vitamin D concentration among Parkinson’s patients was 31.9 nanograms per milliliter, compared with 34.8 nanograms among Alzheimer’s patients, and 37 nanograms among healthy people. The proportion of patients with the lowest levels of vitamin D (vitamin D deficiency) was “significantly” higher among patients with Parkinson’s.

The study was published in the journal Archives of Neurology.

“We found that vitamin D insufficiency may have a unique association with Parkinson’s which is intriguing and warrants further investigation,” said study author Marian Evatt from Emory University in Atlanta, Georgia. Dr. Evatt explained that the part of the brain affected by the disease has a high number of vitamin D receptors, which may suggest a possible association with low levels of vitamin D in Parkinson’s sufferers.

At present there is no cure for Parkinson’s disease, a degenerative disorder of the central nervous system that impairs the sufferer’s motor skills and their speech. Parkinson’s disease is both chronic and progressive. Parkinson’s occurs when the brain cells that produce dopamine are slowly destroyed. But there are several therapies and drugs that provide significant relief from its symptoms, including deep brain stimulation, which is a surgical treatment involving the implantation of a medical device called a brain peacemaker. Deep brain stimulation is one surgical treatment option available for patients who do not experience relief from medications. For many patients, the device called a neurostimulator provides considerable relief.

The most common symptoms of Parkinson’s are tremour, stiffness and slowness of movement, normally caused by the insufficient formation and action of dopamine, which is produced in the dopaminergic neurons of the brain. Secondary symptoms may include high level cognitive dysfunction and subtle language problems. Other symptoms include disorders of mood, behaviour, thinking and sensations. The smell problems were also associated with the onset of the disease, like other known early signs such as more coffee consumption, smoking, less frequent bowel movements, lower cognitive function and excessive daytime sleepiness. It appears that olfactory problems precede the onset of Parkinson’s by around four years.

Vitamin D, also known as the “sunshine vitamin,” helps the body absorb calcium and is considered important for bone health. Vitamin D3 is produced when the skin is exposed to sunlight. It protects the bones and works like a natural anti-cancer agent. Vitamin D is also found in many dietary sources such as fish, eggs, fortified milk and cod liver oil.

It is estimated that 50 to 60 percent of people do not have the satisfactory vitamin-D status. People older than 50 need a higher dose because the body’s ability to convert the vitamin D into its active form (cholecalciferol) begins to decline at age 50.

Previous studies have shown that vitamin D deficiency is associated with a higher incidence of several forms of cancer, high blood pressure, diabetes, obesity and the risk of developing osteoporosis and multiple sclerosis.