Supplements for Parkinson’s — research explained

Claire Bale
Parkinson’s UK
Published in
7 min readOct 17, 2018


Eating a balanced diet is usually the best advice for getting all the vitamins, minerals and nutrients we need to keep our bodies healthy and working well.

There’s no clear scientific evidence that people with Parkinson’s should take supplements but it is an active area of research. So in this blog we round up the current research on the supplements we get asked about most.

As always, please bear in mind that the information provided here describes emerging research and should not be treated as medical advice, so before deciding to take supplements of any kind, speak to your doctor or specialist.

Vitamins and minerals

Vitamins and minerals are nutrients your body needs in small amounts to work properly and stay healthy. Most people should get all the nutrients they need by having a varied and balanced diet, but here we highlight a few which research has suggested may play a role in Parkinson’s.

Vitamin D

Vitamin D helps regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy. The body makes vitamin D when the skin is exposed to direct sunlight, but there are small amounts present in certain foods.

What does the research say?
A 2016 paper which reviewed the evidence from 20 different studies (including both studies in animals and people) found that higher vitamin D levels are linked to a lower risk of Parkinson’s and that people with the condition tend to have lower vitamin D levels.

In addition, studies have indicated that people with Parkinson’s with higher vitamin D levels tend to have better mobility and research in rats and mice indicates that vitamin D may have protective properties. However, the authors called for more studies in people to confirm these potential benefits.

Vitamin B1 (thiamine)

Thiamine is found in many types of food. Good sources include: peas, fresh and dried fruit, eggs, wholegrain breads, some fortified breakfast cereals and liver. Thiamine can’t be stored in the body, so you need it in your diet every day.

What does the research say?
In 2013, a short report on three people with Parkinson’s treated with thiamine supplements was published which described promising improvements in symptoms.

Results from a small trial of thiamine published in 2015 also suggested improvements in symptoms with thiamine. However this study was open-label, which means that the researchers and the participants knew who was receiving thiamine, so the results could have been impacted by the ‘placebo-effect’.

Vitamin B3 (niacin)

Vitamin B3, also known as niacin, helps release energy from the foods we eat and keep the nervous system and skin healthy. There are two forms of niacin — nicotinic acid and nicotinamide — both of which are found in food. Our cells then convert these into NAD+ which is vital in a range of processes inside cells.

What does the research say?
According to a 2018 summary of current research, levels of NAD+ decrease as we age and are further reduced in people with Parkinson’s. Research has also shown that people who eat more foods containing niacin may have a lower risk of developing the condition.

It’s not clear yet whether boosting levels of vitamin B3 (niacin) has benefits for people with Parkinson’s. A recent small clinical trial of niacin showed encouraging signs of benefit and now larger and longer studies are underway.


Iron is important in making red blood cells, which carry oxygen around the body. Good dietary sources of iron include red meat, beans, nuts, dried fruit, fortified cereals and dark-green leafy veg like curly kale.

What’s does the research say?
A US study compared food intake between people recently diagnosed with Parkinson’s and people of a similar age without the condition. The researchers found that people with a high iron intake had an increased risk of developing the condition compared with those with a low iron intake. And people who had a high dietary intake of both iron and manganese had the highest risk.

Initial findings from a study conducted in 1000 people with Parkinson’s found that those who ate more beef (which contains high levels of iron) or took iron supplements were more likely to experience a faster progression.

There are now drugs — like deferiprone — that help the body to remove excess iron being tested in clinical trials to assess their potential benefits for people with the condition.


Antioxidants are chemicals thought to protect against the harmful effects of free radicals — chemicals naturally produced in cells and known to cause damage. We naturally produce our own antioxidants and also absorb them in our diets.

There is currently no firm evidence to suggest that people with Parkinson’s should take antioxidant supplements but let’s take a look at two that are being investigated.

Coenzyme Q10

Coenzyme Q10 occurs naturally inside the cells in the body. It’s an important player in the production of energy and an antioxidant.

What does the research say?
A 2017 study which analysed the data from 8 previous trials provided evidence that Coenzyme Q10 is safe in people with Parkinson’s but no more effective than a placebo in terms of improving symptoms.

The authors concluded that there’s insufficient evidence to recommend it for people with Parkinson’s.


Glutathione is an antioxidant that occurs naturally inside the body. It is not easily absorbed into the bloodstream though so N-acetyl-cysteine (or NAC) — a precursor that the body can convert into glutathione — is also being investigated.

What does the research say?
Studies using postmortem brain tissue have suggested that glutathione levels are low in brain areas affected in Parkinson’s. While experiments have shown that NAC can prevent the Parkinson’s-like damage to brain cells normally caused by the chemical toxin MPTP in mice. Read more in this recent review.

The evidence in people with Parkinson’s is not clear cut. A small exploratory study published in 2016 showed promising effects in brain scans which offered hope that NAC supplements might have positive effects on dopamine function and potentially on symptoms. Whereas, results from a small, short clinical trial published in 2017 showed no difference in quality of life between glutathione and placebo.

Larger and longer clinical trials with NAC are ongoing and will hopefully give us more information.

Other supplements and dietary factors

Finally, there are many other supplements and particular aspects of diet that are being investigated for Parkinson’s.

Again, more research is needed before we can be sure of their effects, but here are three that have shown some potential.

Fish oil (omega 3)

Omega-3 is a family of fatty acids important for the growth and development of brain cells. It is made in our bodies, but very slowly, so we mostly get it from our diet. Oily fish, such as mackerel, tuna, herring, and salmon, have high levels of omega-3.

What does the research say?
It’s not clear whether people with Parkinson’s have reduced levels of omega-3 inside the brain and lab studies have produced conflicting results — some show protective effects but others suggest they may contribute to the build-up of toxic alpha-synuclein.

There have not been any large, long-term clinical trials so far but a recent study in 60 people with Parkinson’s suggested that omega-3 combined with vitamin E improved symptoms over a 12 week period. Another recent, small trial in the US is investigating whether omega-3 supplements may be helpful for dyskinesia and results are expected soon.

Curcumin (turmeric)

Curcumin is a bright yellow chemical produced by some plants. It is found in turmeric and research suggests it may have both anti-inflammatory and antioxidant properties.

What’s does the research say?
Studies in the lab both in cells and animals have suggested that curcumin may have potentially protective effects for Parkinson’s. However, curcumin is not easily absorbed into the bloodstream and so far there have not been any clinical trials to see whether these effects hold true in people.


Caffeine is a chemical stimulant found naturally in some plants. Caffeine is found in coffee, tea, cola and chocolate. As well as being a stimulant (which helps keep us awake), caffeine has antioxidant, anti-inflammatory and other protective properties.

What does the research say?
Population studies suggest that caffeine consumption is associated with a decreased risk of developing Parkinson’s — but this effect seems to be stronger in men than women. While further research has revealed that people with particular genetic variations may benefit most from the protective effects of caffeine.

Results published recently from a small clinical trial showed no difference in movement symptoms of Parkinson’s between participants who received caffeine supplements compared to a placebo.

What have we missed?

We’ve tried to cover the main diets that we are asked about in relation to Parkinson’s, and that have at least some research evidence behind them, but if we’ve missed one then let us know in the comments below and we’ll add it if we can.

Want to read more?

You can read more about nutrition in Parkinson’s, and how researchers are using a new approach to investigate the influence of diet and lifestyle factors, in our previous blog about nutrition.

This blog is not meant as health advice. You should always consult a qualified health professional or specialist before making any changes to your medications or lifestyle.



Claire Bale
Parkinson’s UK

Head of Research Communications and Engagement, Parkinson’s UK