Study Explores Connection Between Vitamin Deficiencies, Chronic Fatigue, and Low Motivation

Feeling constantly drained may not always be just a sign of stress or poor sleep. A new study suggests hidden vitamin deficiencies could also be quietly affecting energy, motivation, and daily performance.

Researchers at Osaka Metropolitan University found that higher blood levels of homocysteine, a molecule linked to low vitamin B12 and folate (vitamin B9), were associated with greater fatigue and reduced motivation in otherwise healthy adults.

The findings, published in the journal Nutrients, add to growing evidence that nutrition may play a larger role in chronic fatigue than many people realize.

The research team studied nearly 600 healthy Japanese participants. Scientists measured blood levels of homocysteine, folate, and vitamin B12, while also assessing fatigue and motivation using established psychological questionnaires.

The results showed a clear pattern: people with higher homocysteine levels tended to have lower levels of vitamin B12 and folate, regardless of sex.

Researchers then analyzed men and women separately while accounting for factors such as age, sleep duration, workload, and dietary habits.

Among men, higher homocysteine levels were linked to greater physical fatigue. Among women, elevated levels were associated with reduced motivation.

Homocysteine is already known as a biomarker connected to cardiovascular disease, dementia, and bone fractures. However, the new findings suggest it may also reflect nutritional imbalances that influence everyday energy and mental drive.

Vitamin B12 and folate are essential nutrients involved in red blood cell production, nerve function, and energy metabolism. Deficiencies can develop gradually, especially in people with unbalanced diets or limited intake of nutrient-rich foods.

Foods rich in folate include leafy greens, beans, citrus fruits, and broccoli, while vitamin B12 is commonly found in meat, fish, eggs, and dairy products.

As modern life leaves many people overworked and exhausted, the study suggests that what is missing from the plate may sometimes matter just as much as the hours lost from sleep.

REFERENCE: Kanouchi, H., et al. (2026). Associations of Plasma Homocysteine Reflecting Vitamin B12 and Folate Status with Fatigue-Related Outcomes in Healthy Adults. Nutrients. DOI: 10.3390/nu18060941. https://www.mdpi.com/2072-6643/18/6/941