Effects of Vitamin B3 on Brain Energy and Cognitive Performance

The human brain is one of the most energy-demanding organs in the body, consuming approximately 20% of total energy at rest. This high metabolic requirement means that even subtle disruptions in cellular energy production can affect cognitive performance over time. Among the nutrients involved in maintaining cerebral energy metabolism, vitamin B3 (niacin and its derivatives) plays a central biochemical role.

Vitamin B3 is a precursor to nicotinamide adenine dinucleotide (NAD⁺), a coenzyme essential for mitochondrial function, oxidative metabolism, DNA repair, and neuronal resilience. In recent years, interest in vitamin B3, particularly nicotinamide riboside (NR) and nicotinamide, has expanded beyond deficiency prevention toward its potential role in cognitive health and brain aging.

In this article, we break down what recent science reveals about vitamin B3, its role in supporting brain energy, and whether it truly impacts cognitive performance.

Vitamin B3, NAD⁺, and Brain Energy Metabolism

Vitamin B3 exists in several biologically relevant forms, including niacin (nicotinic acid), nicotinamide, and nicotinamide riboside. All serve as precursors for NAD⁺ synthesis. NAD⁺ is indispensable for cellular energy production, acting as an electron carrier in different reactions.

Neurons are particularly sensitive to NAD⁺ availability due to their limited energy storage capacity and reliance on mitochondrial efficiency. Age-related declines in NAD⁺ levels have been documented in both peripheral tissues and the brain, and are associated with mitochondrial dysfunction, increased oxidative stress, and impaired synaptic function [1].

From a biological standpoint, maintaining adequate vitamin B3 intake supports the biochemical infrastructure required for neuronal energy homeostasis.

Research on nutrition and brain health doesn’t all answer the same question in the same way. Some studies look at what happens when people take a specific form of vitamin B3, others examine how long-term dietary habits relate to cognition, and some focus on what happens at the cellular level. The sections below walk through each of these perspectives, building a clearer picture of how vitamin B3 may influence brain energy and cognitive performance.

 What We See When Vitamin B3 Is Tested Directly

Nicotinamide riboside has been studied extensively as a strategy to raise systemic NAD⁺ levels in humans. Human supplementation studies consistently show that NR is effectively absorbed and increases NAD⁺ metabolites in blood and tissues, confirming biological availability. Beyond its role in energy metabolism, short-term NR supplementation in older adults has also been associated with reductions in circulating inflammatory markers, suggesting a potential anti-inflammatory effect alongside its metabolic actions [1,2].

However, evidence for direct cognitive improvement remains limited.

In people experiencing ongoing symptoms after COVID-19, supplementation with nicotinamide riboside has been shown to raise NAD⁺ levels in the body. Despite this clear metabolic effect, improvements in attention, executive function, and other measured aspects of cognition were not consistently observed. Some participants did report feeling less fatigued and mentally clearer over time, but these changes were modest and varied between individuals [3].

Similar findings have been reported in older adults with mild cognitive impairment. In a small human study, nicotinamide riboside supplementation safely increased blood NAD⁺ levels over 10 weeks, confirming effective uptake and engagement of energy-related pathways. Regardless of this clear metabolic response, overall cognitive performance remained stable, with no meaningful changes observed in global cognitive scores or other neurocognitive measures over the course of the intervention. Measures of brain blood flow showed some localized changes, but these findings were modest and not clearly linked to cognitive improvement [4,5].

Taken together, this body of evidence suggests that vitamin B3 derivatives are effective at supporting the biochemical pathways involved in brain energy metabolism, but their impact on short-term cognitive performance in clinical populations appears limited and may depend on individual context, baseline status, and duration of use.

What Long-Term Diet Patterns Tell Us

Looking beyond supplementation, long-term dietary habits offer additional insight into how vitamin B3 may relate to brain health. Studies examining everyday nutrient intake suggest that people who consistently consume higher amounts of niacin tend to perform better on measures of memory, attention, and processing speed later in life [4].

In large population samples of older adults, higher dietary niacin intake has been linked with a lower likelihood of cognitive impairment compared with lower intake levels [4]. Evidence from another long-term follow-up study points in the same direction: individuals with higher cumulative intake of B vitamins, including niacin, from early adulthood appear to show better cognitive function in midlife [5].

While these findings cannot prove a direct cause-and-effect relationship, they show how maintaining adequate vitamin B3 intake over time supports cognitive health as part of an overall nutritious dietary pattern.

What Biology Helps Us Understand

Experimental research indicates that restoring NAD⁺ availability through vitamin B3–related pathways supports key cellular functions in the brain, including mitochondrial activity and metabolic efficiency. These processes are central to neuronal health, particularly in tissues with high energy requirements and limited capacity to tolerate metabolic stress [1].

NAD⁺ also acts as a required substrate for enzymes involved in cellular maintenance and stress responses, such as those regulating DNA repair and adaptive responses to damage. Dysregulation of these pathways has been linked to mechanisms associated with brain aging and vulnerability to neurodegeneration [1].

In other words, these studies support a mechanistic link between vitamin B3 availability, NAD⁺ metabolism, and the maintenance of brain energy balance over time, helping to explain why adequate vitamin B3 intake may be relevant for long-term cognitive resilience.

Interpreting the Evidence: Why Results Differ

When viewed together, the evidence on vitamin B3 and cognition points to a consistent theme: effects vary depending on context, timing, and the way outcomes are measured. Several factors help explain why results differ across studies:

• Baseline nutritional status: Individuals with lower habitual intake of vitamin B3 may be more likely to benefit than those who are already nutritionally sufficient.

• Duration of exposure: Supporting brain energy metabolism is likely a gradual process. Short-term supplementation may not be long enough to translate into measurable changes in cognitive performance.

• Sensitivity of cognitive measures: Standard cognitive tests may not capture subtle metabolic or protective effects occurring at the cellular level.

• Population differences: Responses may vary between healthy adults, older individuals, and people with existing cognitive concerns.

This means that vitamin B3 is unlikely to function as an acute cognitive enhancer. Instead, it appears better positioned as a supportive, long-term contributor to brain health, particularly as part of an overall pattern of adequate nutrition and metabolic resilience.

What to Expect from Vitamin B3 in Real Life

When the science is translated into practical terms, the role of vitamin B3 in brain health becomes clearer and more nuanced:

• Vitamin B3 supports brain energy at a fundamental level: Its primary role in NAD⁺ production makes it essential for the cellular processes that keep neurons functioning efficiently.

• Dietary adequacy matters more than quick fixes: Higher niacin intake from everyday foods has been consistently linked with better cognitive performance in later life. Vitamin B3 supplementation may offer an additional way to support NAD⁺-related metabolic pathways as part of a consistent wellness routine.

• Supplements raise NAD⁺, not necessarily cognition: Vitamin B3 derivatives reliably increase NAD⁺ levels in the body, but clear, short-term improvements in cognitive performance have not yet been demonstrated.

Rather than acting as a stand-alone solution, vitamin B3 appears to work best within a broader lifestyle context that supports metabolic and vascular health, including regular physical activity, adequate sleep, and cardiovascular risk management.

Conclusion: Fueling the Brain for the Long Term

Vitamin B3 sits at the intersection of nutrition, cellular energy metabolism, and brain function. While current human studies do not support its use as a cognitive enhancer on its own, both population-level data and biological evidence suggest it plays a meaningful role in maintaining the metabolic foundation that supports cognitive resilience over time. In that sense, vitamin B3 is less about sharpening the mind overnight and more about sustaining the energy systems the brain depends on for the long run.

If you're a practitioner interested in all things vitamin B3, particularly niacin, take a look at Tro+ Calm, our practitioner-only, extra-strength, and next-generation formulation designed to help patients relieve stress, reduce anxiousness, and quiet the mind when they need it most.

Read more about vitamin B3 in the blogs below:

• Niacin vs. Niacinamide: Understanding Vitamin B3, Benefits, and Side Effects
• The Difference Between “Flush” and “No-Flush” Niacin
• Does niacin cross the blood-brain barrier?
• The Connection Between Vitamin B3 (Niacin) Deficiency and Chronic Fatigue
• Does Vitamin B3 Help Hair Growth?
• Does Vitamin B3 Increase Testosterone?
• Vitamin B3 and Your Mitochondria: What Really Happens Inside Your Cells

References 

1. Fang, E. F., Lautrup, S., Hou, Y., Demarest, T. G., Croteau, D. L., Mattson, M. P., & Bohr, V. A. (2017). NAD+ in Aging: Molecular Mechanisms and Translational Implications. Trends in molecular medicine, 23(10), 899–916. 

2. Elhassan, Y. S., Kluckova, K., Fletcher, R. S., Schmidt, M. S., Garten, A., Doig, C. L., Cartwright, D. M., Oakey, L., Burley, C. V., Jenkinson, N., Wilson, M., Lucas, S. J. E., Akerman, I., Seabright, A., Lai, Y. C., Tennant, D. A., Nightingale, P., Wallis, G. A., Manolopoulos, K. N., Brenner, C., Lavery, G. G. (2019). Nicotinamide Riboside Augments the Aged Human Skeletal Muscle NAD+ Metabolome and Induces Transcriptomic and Anti-inflammatory Signatures. Cell reports, 28(7), 1717–1728.e6. 

3. Wu, C. Y., Reynolds, W. C., Abril, I., McManus, A. J., Brenner, C., González-Irizarry, G., Gutiérrez-Martínez, L., Sun, O., Rosand, J., Tanzi, R. E., Arnold, S. E., & Guzmán-Vélez, E. (2025). Effects of nicotinamide riboside on NAD+ levels, cognition, and symptom recovery in long-COVID: a randomized controlled trial. EClinicalMedicine, 89, 103633.

4. Orr, M. E., Kotkowski, E., Ramirez, P., Bair-Kelps, D., Liu, Q., Brenner, C., Schmidt, M. S., Fox, P. T., Larbi, A., Tan, C., Wong, G., Gelfond, J., Frost, B., Espinoza, S., Musi, N., & Powers, B. (2024). A randomized placebo-controlled trial of nicotinamide riboside in older adults with mild cognitive impairment. GeroScience, 46(1), 665–682.

5. Qin, B., Xun, P., Jacobs, D. R., Jr, Zhu, N., Daviglus, M. L., Reis, J. P., Steffen, L. M., Van Horn, L., Sidney, S., & He, K. (2017). Intake of niacin, folate, vitamin B-6, and vitamin B-12 through young adulthood and cognitive function in midlife: the Coronary Artery Risk Development in Young Adults (CARDIA) study. The American journal of clinical nutrition, 106(4), 1032–1040.