Study suggests lower vitamin K levels linked to reduced lung function

Patients who have low vitamin K levels have a reduced ventilatory capacity and are more likely to self-report asthma, COPD or wheezing, according to a study by researchers from Copenhagen University Hospital and the University of Copenhagen.

The study, which was published in the journal ERJ Open Research, set out to assess whether lower vitamin K status was associated with lung function and lung disease/symptoms. The researchers focused on the measurement of dephosphorylated-uncarboxylated MGP (dp-ucMGP), which serves as an inverse plasma biomarker for vitamin K status.

The team recruited members of the general population and invited them to a health examination to complete questionnaires and undergo spirometry, together with measurement of plasma dp-ucMGP. Lung function assessments were the forced expiratory volume during the first second (FEV₁) and forced vital capacity (FVC). FEV₁/FVC-ratio was calculated as the ratio between these two measurements.

In the questionnaires, researchers asked participants whether they had ever been diagnosed with either asthma or COPD, or whether they had experienced wheezing during the last 12 months. They then used multivariable logistic regression to assess the associations between dp-ucMGP and the dichotomous variables, COPD, asthma and wheezing.

Vitamin K status and lung function

A total of 4,092 individuals aged 24-77 years were included in the analysis.

Lower vitamin K status, reflected by higher dp-ucMGP levels, was associated with lower FEV₁ and FVC. However, dp-ucMGP was not associated with the FEV₁/FVC-ratio. A lower status was significantly associated with COPD (Odds ratio, OR = 2.24, 95% CI 1.53 – 3.27), wheezing (OR = 1.81 95% CI 1.44 – 2.28) and asthma (OR = 1.44 95% CI 1.12 – 1.83).

Lead author of the study, Dr Torkil Jespersen, said: ‘We already know that vitamin K has an important role in the blood, and research is beginning to show that it’s also important in heart and bone health, but there’s been very little research looking at vitamin K and the lungs.

‘To our knowledge, this is the first study on vitamin K and lung function in a large general population. Our results suggest that [it] could play a part in keeping our lungs healthy.‘

The vitamin is found in leafy green vegetables, vegetable oils and cereal grains. It plays a role in blood clotting, although, clinically, vitamin K antagonists are used as anticoagulants to control bleeding.