Like many drugs, levodopa, the most common drug used to treat Parkinson’s disease (PD), can create nutrient deficiencies with serious side effects taken over time.
PD is a progressive neurological disease in which brain cells that produce the neurotransmitter dopamine gradually die off. Low levels of dopamine cause various movement and non-movement related dysfunctions. The drugs that treat PD either replace or enhance dopamine, and central among these drugs is levodopa. Levodopa is converted into dopamine in your body. It is usually combined with another drug, carbidopa, which prevents levodopa from being converted into dopamine too soon, before it reaches the brain. The combination of levodopa and carbidopa is called Sinemet.
Past studies have linked carbidopa with low vitamin B6 (pyridoxine) levels. In a recent study, Spanish researchers measured vitamin B6 levels in 24 patients being treated with levodopa/carbidopa. Six of these patients were being given the drug combo by infusions into their small intestine; the others took the drug orally. Of the 24 patients, 19 were low in B6, and those given the infusions were especially low. Four out of the six being given infusions had levels so low they couldn’t even be detected. Of the patients with non-detectable levels, two showed evidence of neuropathy (nerve pain), which is a symptom of B6 deficiency and a common problem in PD.
Commenting on this article in the Townsend Letter, Dr. Alan Gaby, an expert in using nutrition in medicine, suggested that patients with Parkinson’s disease who are taking levodopa/carbidopa supplement with a moderate dose (25-50 mg/day) of vitamin B6.
He noted that some doctors hesitate to give patients taking levodopa supplemental vitamin B6 based on reports that it can make PD symptoms worse; but that these problems occur only when levodopa is taken without carbidopa. In fact, a 1971 study showed that supplementing with 25 mg daily of vitamin B6 enhanced the effectiveness of levodopa as long as it was taken with carbidopa.
Treatment with levodopa can lead to deficiencies in other vitamins as well, such as vitamin B3 (niacin), folic acid and vitamin B12.
Such deficiencies can produce neurological symptoms that are falsely attributed to PD. For example, according to neurosurgeon Russell Blaylock, M.D., B12 deficiency can produce confusion and lack of mental clarity, poor memory, insomnia, nervousness, weakness, fatigue, imbalance, anxiety, depression, tremors, and dementia—all symptoms of PD.
Deficiencies in B12 are common, especially as you age. Not too long ago, Dr. Blaylock says, the elderly got regular B12 shots, at least every year if not monthly. Since that time, rates of Alzheimer’s, Parkinson’s, and other neurodegenerative diseases have skyrocketed.
For most people, taking two tablets of our daily Multivitamin insures against deficiencies in the B vitamins. But some will need our B-Complex formula in addition (i.e. those under considerable stress, including the stress of having a chronic illness.)
If you’re over age fifty, we recommend taking one of our B12/folate sublingual (under-the-tongue) tablets daily for extra protection and extra energy. (The sublingual delivery system is equivalent to the traditional “B12 shot,” and a lot less painful!)
If you have a chronic illness, whether or not you’re taking medications for it, it would be wise to get checked periodically by a functional medicine doctor or other alternative healthcare practitioner skilled in testing for and evaluating nutritional deficiencies.
- Rojo-Sebastian A. Vitamin B6, deficiency in patients with Parkinson’s disease treated with levodopa/carbidopa. Clinical Neuropharmacology. September/October 2020;43(5):151-157.
- Gaby A. Vitamin B6, Parkinson’s disease and levodopa/carbidopa, Gaby’s Literature Review. Townsend Letter, October 2021;459:12.
- Yahr MD. Pyridoxine, levodopa and L-alpha-methyldopa hydrazine regimen in Parkinsonism. Journal of the American Medical Association. June 1971;216(13):2141.
- Blaylock R. Vitamin B12 deficiency and dementia. The Blaylock Wellness Report. February 2012.