Supplementation with vitamins K2 and D3 appear to have a beneficial effect on long COVID symptoms compared to standard of care (SOC) treatment, according to a new randomized, controlled human clinical trial published in Nutrients. The research also found that supplementation exhibited inflammatory-modulating properties, and potential gut health benefits of this vitamin combo.

The trial involved 151 adults who were previously diagnosed with COVID-19 infection that experienced prolonged, recurrent, or newly-developed symptoms more than three months after their positive test result. Participants were assigned to receive a standard treatment, or a daily supplement containing 240 mcg of vitamin K2 as MK-7 (marketed by ingredient supplier Balchem Human Nutrition and Health as K2Vital MCT) and 50 mcg of vitamin D for 24 weeks.

The authors reported that at the end of the treatment period, the active treatment group experienced a 7.1% decrease in the proportion of participants who had a Long COVID Index (a tool used to classify and diagnose people with long COVID) of greater than 12, versus a 7.2% increase in the standard of care group. The average number of long COVID symptoms remained stable in the vitamin K2/D3 arm but increased in the SOC arm. The most frequent symptoms were fatigue, problems thinking, pain in any part of the body, shortness of breath, and change in smell or taste. There was a notable decrease in participants suffering from body pain and post-exertional malaise in the treatment arm, suggesting that the vitamins had a beneficial effect on muscle-related symptoms.

The treatment group also experienced reductions in several inflammatory markers and oxidized LDL levels, suggesting the potential immune and cardiovascular health benefits of the vitamins. Supplementation with these ingredients was also linked to decreased markers of gut permeability and fungal translocation, each of which is thought to be a factor in the pathophysiology of long COVID.

“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. We observed a treatment effect of K2 andD3 on reducing the Long COVID Research Index and total number of symptoms, highlighting the promising impact of vitamin K2 and D3 supplementation in attenuating long COVID,” said Dr. Grace McComsey, MD, FIDSA, lead author, professor of medicine and pediatrics and vice dean for clinical and translational research at Case Western Reserve University, and research integrity officer at University Hospitals.

“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. We’re proud that our K2Vital ingredient played a role in this study, and the findings hold great potential for the future,” said Trygve Bergeland, director of nutrition science at Balchem Human Nutrition and Health.