Vitamin B3, also known as niacin, plays a crucial role in our body’s metabolism. It is obtained from food and converted into a molecule called NAD+ (nicotinamide adenine dinucleotide), which is essential for energy production in cells. Vitamin B3 could be of particular importance for people with Parkinson’s, as there is evidence that it can slow down the breakdown of brain cells and thus have a positive effect on the course of the disease.
The importance of NAD+ in the brain
NAD+ is a key molecule in many biochemical processes, including DNA repair and energy production in the mitochondria, the powerhouses of cells. As we age, NAD+ levels in the brain naturally decline, which is associated with the ageing process and neurodegenerative diseases such as Parkinson’s disease. Especially in diseases that accelerate ageing, such as Parkinson’s, an early reduction in NAD+ levels has been observed. This decrease in NAD+ can lead to a more rapid breakdown of brain cells, which has a negative impact on the motor and cognitive abilities of those affected.
Preclinical studies on vitamin B3 in Parkinson’s disease
In view of these correlations, scientists hypothesised that an increase in NAD+ levels through the intake of vitamin B3 could have a positive influence on the course of Parkinson’s disease. In a preclinical study, David C. Schöndorf and his colleagues from the University of Tübingen investigated the effect of nicotinamide riboside (NR), a form of vitamin B3 that has a similar function to niacin but a different molecular structure 1. Their research on a fruit fly model of Parkinson’s disease yielded promising results: NR was able to increase NAD+ levels and significantly prevent the loss of brain cells as well as motor degradation processes.
A step towards B3 therapy
Following the encouraging preclinical results, the safety and tolerability of NR were investigated in a phase 1 clinical trial at Haukeland University Hospital in Norway 2. This study involved 30 people with newly diagnosed Parkinson’s who received either 1000 mg NR or a placebo for one month. The results were promising: the researchers were able to show that NR reached the participants’ brains and that 10 out of 15 people who had taken NR had higher NAD+ levels in the brain. These patients also showed improvements in motor and non-motor symptoms as assessed by the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS).
A subsequent phase 1 study confirmed the safety of NR at higher doses. Participants took 3000 mg of NR daily for one month without experiencing moderate or severe side effects 3. These results laid the foundation for further studies to determine the optimal dosage and long-term effects of NR in Parkinson’s patients.
Phase 2 and Phase 3 studies on vitamin B3 in Parkinson’s disease
Two further clinical trials are currently underway to further investigate the potential of vitamin B3 in the treatment of Parkinson’s disease. A phase 2 study is investigating the optimal dosage of NR 4. Participants are taking gradually increasing doses of 1000 to 3000 mg to find out which amount is most effective and yet well tolerated.
In parallel, a phase 3 study is investigating whether the daily intake of 1000 mg NR over a period of one year can delay the course of the disease in patients with early-stage Parkinson’s disease 5. This study is of great importance as it will not only evaluate the long-term effect of NR on the course of the disease, but also possible long-term side effects.
Mechanisms of the effect of vitamin B3 in Parkinson’s disease
The exact mechanism by which vitamin B3 or NR works in Parkinson’s is not yet fully understood. However, it is thought that the increase in NAD+ levels could trigger several positive effects in the brain. These include promoting DNA repair, reducing inflammation and improving mitochondrial function, which is often impaired in Parkinson’s patients. Together, these mechanisms could help to slow the loss of brain cells and alleviate the symptoms of the disease.
Vitamin B3 in the diet and as a food supplement
Vitamin B3 occurs naturally in foods such as red meat, fish, brown rice and pulses. Whilst a balanced diet is usually sufficient to meet daily requirements, people with Parkinson’s may benefit from taking additional vitamin B3 or NR. However, it is important to emphasise that supplements should always be taken in consultation with a doctor, especially at the higher doses used in the studies.
Conclusion: therapeutic potential of vitamin B3 for Parkinson’s disease
The results of research to date suggest that vitamin B3, particularly in the form of nicotinamide riboside, could be a promising supplement in the treatment of Parkinson’s disease. By increasing NAD+ levels in the brain, it could slow the breakdown of brain cells and alleviate the symptoms of the disease. Although further studies are needed to determine the optimal dosage and long-term effects, the results so far offer hope for new approaches in Parkinson’s therapy.
For people with Parkinson’s who are considering supplementing with vitamin B3, it is important to do so in close consultation with a specialist. The ongoing clinical studies will provide further findings in the coming years, which will hopefully help to positively influence the course of Parkinson’s disease.
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References
- Schöndorf DC, Ivanyuk D, Baden P, et al. The NAD+ Precursor Nicotinamide Riboside Rescues Mitochondrial Defects and Neuronal Loss in iPSC and Fly Models of Parkinson’s Disease. Cell Rep. 2018;23(10):2976-2988. doi:10.1016/j.celrep.2018.05.009
- Brakedal B, Dölle C, Riemer F, et al. The NADPARK study: A randomized phase I trial of nicotinamide riboside supplementation in Parkinson’s disease. Cell Metab. 2022;34(3):396-407.e6. doi:10.1016/j.cmet.2022.02.001
- Berven, H., Kverneng, S., Sheard, E. et al. NR-SAFE: a randomized, double-blind safety trial of high dose nicotinamide riboside in Parkinson’s disease. Nat Commun 14, 7793 (2023). https://doi.org/10.1038/s41467-023-43514-6
- https://clinicaltrials.gov/study/NCT05589766
- https://clinicaltrials.gov/study/NCT03568968