New study suggests low b12 and folate may drive persistent tiredness

Feeling constantly tired or low on energy may not only be the result of stress, poor sleep, or a busy lifestyle; a new study suggests that vitamin deficiencies could also play a significant role in chronic fatigue.

Researchers in Japan have found that low levels of vitamin B12 and folate (vitamin B9) may be linked to persistent tiredness, reduced motivation, and overall low energy, even in otherwise healthy individuals.

The study, led by Professor Hiroaki Kanouchi from Osaka Metropolitan University, examined whether nutritional deficiencies could influence fatigue levels by measuring key blood markers in around 600 healthy adults.

Fatigue is generally defined as extreme tiredness that is not relieved by rest or sleep, and it has become increasingly common in modern life due to high workloads, stress, and reduced recovery time. However, researchers say nutrition may be an overlooked factor.

In the study, published in the journal Nutrients, scientists analyzed levels of folate, vitamin B12, and homocysteine a blood substance that tends to rise when these vitamins are deficient.

Participants also completed standardized questionnaires assessing fatigue and motivation.

The results showed that individuals with higher homocysteine levels generally had lower levels of both vitamin B12 and folate, regardless of gender.

Elevated homocysteine was also associated with different fatigue patterns: women were more likely to report reduced motivation, while men more commonly experienced physical fatigue.

Researchers also accounted for additional variables such as age, sleep duration, workload, and diet, strengthening the link between nutritional status and fatigue symptoms.

According to the research team, maintaining adequate intake of vitamin B12 and folate may help regulate homocysteine levels and reduce fatigue-related symptoms.

“To prevent an increase in homocysteine levels, it is important to avoid deficiencies in vitamin B12 and folate. Maintaining a well-balanced diet on a daily basis is essential,” the researchers advised.

While fatigue itself is not considered a disease, experts note that persistent exhaustion can significantly affect daily functioning and overall quality of life.

The findings highlight the importance of nutritional balance in maintaining energy levels, suggesting that addressing vitamin deficiencies could be one factor in managing chronic tiredness alongside lifestyle and sleep habits.