Study shows vitamins K2 and D3 may help reduce symptoms of long COVID

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In a March 2025, press release, global specialty ingredients manufacturer Balchem announced results from a recent clinical trial¹ on the effects of Vitamins K2 MK-7 and D3 on long COVID (LC) symptoms. As noted in the study’s introduction, there is currently no approved treatment for this condition, which can be associated with fungal translocation, gut dysfunction, and enhanced systemic inflammation, as well as symptoms of post-exertional malaise, fatigue, and brain fog. Also noted was the anti-inflammatory effect of vitamins K2 and D3. Researchers hypothesized that supplementation could help decrease systemic inflammation. The single-site randomized controlled study, “Vitamins K2 and D3 Improve Long COVID, Fungal Translocation, and Inflammation: Randomized Controlled Trial,” was published in Nutrients in January 2025. The vitamin K2 MK-7 ingredient provided by Balchem as the patented K2VITAL.

“For the first time, in this randomized controlled clinical trial, we investigated the effects of vitamins K2 and D3 on long COVID symptomatology, as well as markers of immune activation and gut function,” stated study author Grace McComsey, MD, FIDSA in the press release. “We observed a treatment effect of K2/D3 on reducing the long COVID Research Index and total number of symptoms, highlighting the promising impact of vitamin K2/D3 supplementation in attenuating long COVID.”

The study involved 151 participants who were experiencing at least two LC symptoms at least three months after a COVID infection. The participants were randomized into two groups: a standard of care (SOC) or the active group, which received two capsules daily of 240 µg K2 (K2Vital MCT) and 2000 UI vitamin D3, for 24 weeks. Tests were done at baseline, 12, and 24 weeks.

Results of the study included:

• At month 6, the active group showed a reduction in scores on the LC index
• There was also reduction in symptoms of smell or taste, pain in any part of the body, persistent cough, post-exertional malaise, and shortness of breath
• In comparison, the SOC group showed an increase in scores on the LC index and no change in the participants who reported more than two symptoms
• The average number of symptoms stayed the same in the active group and increased in the SOC group

Additionally, compared to the SOC group, the K2/D3 group showed reductions in oxidized LDL, inflammatory markers, and fungal translocation marker, all key factors in immune and cardiovascular health as well as the mechanisms of LC.

Some of the study’s limitations included the lack of longitudinal data on symptom severity, the SOC arm did not receive a placebo, and confounding factors such as diet and exercise were not measured.

Ultimately, researchers concluded that the supplementation was a safe and effective intervention, has the potential for global impact, and further studies could be conducted to confirm the efficacy of the vitamins.

“At Balchem, science is at the heart of everything we do and we are dedicated to collaborating with universities and research institutions to drive scientific progress,” stated Trygve Bergeland, director of nutrition science, Balchem Human Nutrition and Health. “We’re proud that our K2Vital ingredient played a role in this study, and the findings hold great potential for the future.”

Reference

1. Atieh, O.; Daher, J.; Durieux, JC.; Abboud, M.; Labbato, D.; Baissary, J.; Koberssy, Z.; Ailstock, K.; Cummings, M.; Funderburg, NT.; McComsey, GA. Vitamins K2 and D3 Improve Long COVID, Fungal Translocation, and Inflammation: Randomized Controlled Trial. Nutrients 2025. DOI: 10.3390/nu17020304.