Sports nutrition is expanding beyond traditional protein powders and pre-workout supplements, with increasing consumer interest in ingredients that support physical performance and cognitive function. A recent randomized, triple-blind, placebo-controlled crossover trial published in Nutraceuticals reported that healthy male amateur cyclists who took 1 mg of methylcobalamin, an active form of vitamin B12, daily for three days experienced a 4.1% increase in peak power output, a 6.4-percentage-point reduction in fatigue index compared with placebo, and a 4.9% reduction in cognitive reaction time. These findings suggest that short-term methylcobalamin supplementation may be associated with measurable changes in anaerobic and cognitive performance. Beyond sports nutrition, vitamin B12 has also attracted research interest for its potential roles in cognitive function and corneal protection. Other B vitamins, including biotin (vitamin B7) and thiamine (vitamin B1), contribute to hair and skin health, energy metabolism, and normal nervous system function. Together, these findings highlight the potential of B vitamins in functional nutrition, while further research is needed to clarify their applications and benefits across different populations.
From Everyday Fitness to Sports Nutrition: The Emerging Role of Vitamin B12
From protein powders and pre-workout supplements in gyms to functional beverages on convenience store shelves, sports nutrition products are increasingly becoming part of everyday life. According to market data, the global sports nutrition market was valued at approximately $45.6 billion in 2025 and is projected to reach $79.1 billion by 2034, with a compound annual growth rate (CAGR) of 22.2%. Behind this rapid market growth is sustained consumer demand for sports nutrition supplementation.
Recently, a study published in Nutraceuticals reported that healthy male amateur cyclists who took 1 mg of methylcobalamin (vitamin B12, an active form of VB12) daily experienced a significant 4.1% increase in peak power output after just three days. Their fatigue index was significantly lower by 6.4 percentage points compared with the placebo group, while cognitive reaction time was significantly shortened by 4.9%. These findings have brought methylcobalamin into the spotlight as an emerging ingredient in sports nutrition.
1. A Natural Ingredient with Measurable Changes After Three Days
The study was conducted by a team from the High Performance Sport Research Center at the Catholic University of Murcia in Spain. It was a randomized, triple-blind, placebo-controlled crossover clinical trial involving 18 well-trained, healthy male amateur cyclists aged 18–45 years who trained four to six days per week.
During two experimental periods, participants received either methylcobalamin (1 mg/day, administered sublingually) or a placebo for three consecutive days. A seven-day washout period was established between the two periods.
To simulate high-intensity exercise conditions, the researchers used repeated Wingate tests to assess anaerobic capacity. The protocol consisted of five 30-second all-out sprints, with three minutes of recovery between sets. Cognitive reaction speed was evaluated using a reaction-light testing system involving 120 light stimuli.
Image source: Reference [1]
The results were noteworthy. Just three days of methylcobalamin supplementation were associated with significant improvements in three areas: peak power output increased by 4.1%; the fatigue index was significantly lower by 6.4 percentage points compared with placebo, representing an 82.9% reduction; and cognitive reaction time decreased significantly by 4.9%.
More importantly, post-exercise serum vitamin B12 concentrations were significantly positively correlated with changes in peak power output. This finding suggests that even participants who were not vitamin B12 deficient showed improvements in performance following methylcobalamin supplementation.
2. Vitamin B12: An Essential Vitamin Containing a Metal Ion
Vitamin B12, also known as cobalamin, is a polycyclic compound containing trivalent cobalt. It is the only water-soluble essential vitamin that contains a metal ion. As an important micronutrient, it performs several key physiological functions in the human body. From supporting normal blood formation to maintaining nervous system health, this seemingly small but essential vitamin plays an indispensable role.
In addition to its potential applications in sports nutrition, vitamin B12 has attracted growing interest in recent years for its possible roles in specialized areas such as cognitive function and eye health.
1) Potential Benefits for Cognitive Function
Research has found that vitamin B12 supplementation may improve cognitive function. A prospective case-control study showed that patients receiving vitamin B12 supplementation therapy experienced significant improvements in attention and calculation abilities, as well as visuoconstructive abilities. The researchers also recommended that all patients with cognitive impairment should have their vitamin B12 levels assessed.
2) Corneal Protective Effects
Vitamin B12 has also demonstrated potential applications in ophthalmology. Eye drops formulated with 0.01% vitamin B12 and 0.15% hyaluronic acid significantly improved oxidative and inflammatory damage in corneal epithelial cells, showing protective effects in terms of reactive oxygen species (ROS) production and the expression of pro-inflammatory cytokines.
Furthermore, at 36 and 48 hours after corneal scratching, the eye drops containing vitamin B12 achieved significantly better wound closure. These findings suggest that vitamin B12 may enhance the protective effects of hyaluronic acid, accelerate wound healing, and regulate oxidative stress and inflammatory responses.
Although intestinal microbial activity can produce vitamin B12 analogues, these analogues are not biologically active. Their synthesis occurs mainly in the cecum, where the resulting compounds are not absorbed but are instead excreted in feces. This means that the human body cannot rely on its own intestinal microbiota to meet its vitamin B12 requirements and must obtain it through dietary sources or external supplementation.
3. Beyond Vitamin B12: The Powerful B-Vitamin Family
Vitamin B refers collectively to the B-vitamin family, which includes more than a dozen types, nine of which are recognized worldwide as essential vitamins. As water-soluble vitamins that must be obtained through daily dietary intake, B vitamins participate in energy metabolism, help maintain nervous system health, and support healthy skin and hair.
Vitamin B7: The B Vitamin Associated with Hair Health
Vitamin B7, also known as vitamin H or biotin, is a necessary substance for vitamin C synthesis and an essential nutrient for maintaining normal growth, development, and physiological function in the human body.
Vitamin B7 is found primarily in the liver, kidneys, yeast, and milk. It was first discovered in the liver in the 1930s, when researchers observed that it could improve hair loss and skin damage in rats. Modern research has found that vitamin B7 may help improve hair loss, prevent premature graying of hair in adolescents, and play an important role in maintaining skin health.
According to GB 28050-2025, vitamin B7 is the only member of the B-vitamin family permitted to carry the claim that it “helps maintain healthy skin and hair.”
Vitamin B1: The Oldest Discovered B Vitamin
Vitamin B1, also known as thiamine, the antineuritic factor, or the antiberiberi factor, was the first vitamin to be discovered and isolated worldwide. It is found mainly in yeast and in the outer layers and germ of seeds, such as rice bran and wheat bran.
In the body, vitamin B1 exists in the form of thiamine pyrophosphate (TPP), an important coenzyme for multiple enzyme systems involved in the biological oxidation of carbohydrates, fats, and amino acids. It helps convert food into energy, supports normal nerve and heart function, promotes digestion and absorption, and helps strengthen immune function.
With evidence from a clinical study suggesting that methylcobalamin supplementation may improve exercise performance after just three days, vitamin B12 may be poised to move from a supporting ingredient in functional beverages to a more prominent component of sports supplement formulations. However, further studies are needed to confirm these findings and establish the effectiveness of short-term supplementation across broader populations.
References
[1] Martínez-Noguera F J, Alcaraz P E, Blanc F J G, et al. Short-Term Methylcobalamin Supplementation Is Associated with Changes in Anaerobic and Cognitive Performance in Amateur Cyclists: A Randomized Crossover Trial[J]. Nutraceuticals, 2026, 6(2), 35.
[2] https://mp.weixin.qq.com/s/EOVbY6BPKsDgkRpiNlw2hA
[3] Lauer A A, Grimm H S, Apel B, et al. Mechanistic Link between Vitamin B12 and Alzheimer's Disease[J]. Biomolecules, 2022, 12(1): 129. DOI: 10.3390/biom12010129.
[4] Lazzara F, Conti F, Maugeri G, et al. Corneal protective effects of a new ophthalmic formulation based on vitamin B12 and sodium hyaluronate[J]. Frontiers in Pharmacology, 2025.