The Relationship between Dietary Vitamin K and Depressive Symptoms in Late Adulthood: A Cross-Sectional Analysis from a Large Cohort Study (Bolzetta F et al.)
Results of a cross-sectional analysis that was conducted by an international team of researchers and investigated the association between dietary vitamin K and depressive symptoms in a large cohort of North American People have recently been published in a special issue of the Nutrients journal, namely Diet and Mental Health.
For the purpose of this study the authors enrolled 4,375 participants aged 45–79 years from the Osteoarthritis Initiative that includes in its database people at high risk of knee osteoarthritis or having knee osteoarthritis, who were recruited at four clinical centers in the USA. Dietary vitamin K intake was collected through a semi-quantitative food frequency questionnaire – a method widely used for collecting information regarding dietary habits over the previous year – and arbitrarily categorized in four quartiles while using the following cut-offs: 83, 138, 232 ug/day. Moreover, the researchers modelled the dietary vitamin K intake as per 100 ug/day increment. Depressive symptoms were diagnosed using the 20-item Center for Epidemiologic Studies-Depression (CES-D) ≥ 16. To investigate the associations between vitamin K intake and depressive symptoms, logistic regression analysis were run, which adjusted for potential confounders. Overall, 437 (=10%) subjects had depressive symptoms. After adjusting for 11 confounders, people with the highest dietary vitamin K intake had lower odds of having depressive symptoms (OR = 0.58; 95%CI: 0.43–0.80). This result was only present in people not taking vitamin D supplementation.
The researchers arrived at a conclusion that, “Higher dietary vitamin K intake was significantly associated with a lower presence of depressive symptoms, also after accounting for potential confounders, suggesting a role for this vitamin in the prevention and treatment of depressed mood. However, future longitudinal and intervention studies are needed to confirm or refute our findings.”
“The vitamin K intake was calculated by the authors of this paper as the sum of vitamin K supplementation (if any) and of dietary intake of vitamin K, as assessed by the diet recall questionnaire, so they did not aim to look specifically at vitamin K2,” says Dr. Katarzyna Maresz, president of the International Science and Health Foundation. “Nonetheless there are a lot of papers which show that vitamin K2 is important for the brain function,” she adds and cites some important observations that have already been made by Ferland (2013), “[…] vitamin K-dependent proteins (VKDPs), not associated with blood coagulation, also contribute to the brain function. In addition to the VKDPs, vitamin K participates in the nervous system through its involvement in sphingolipid metabolism, a class of lipids widely present in brain cell membranes. […] Also, there is growing evidence that [K2] the K vitamer, menaquinone-4, has anti-inflammatory activity and offers protection against oxidative stress.”2 “Finally, although limited in numbers, reports point to a modulatory role of vitamin K in cognition,” Dr. Maresz emphasizes. “In one of the studies higher dietary phylloquinone intake was associated with better cognition and behavior among older adults,3 a rat model in another study provides further evidence that targeted depletion of MK4 in brain is associated with cognitive impairment,4 and yet another study highlights the importance of dietary vitamin K as a potentially protective cognitive factor; it also provides evidence for the correlation between cognition and inflammation,5” she further mentions.
- Bolzetta F, Veronese N, Stubbs B, Noale M, Vaona A, Demurtas J, Celotto S, Cacco C, Cester A, Caruso MG, Reddavide R, Notarnicola M, Maggi S, Koyanagi A, Fornaro M, Firth J, Smith L, Solmi M (2019) The Relationship between Dietary Vitamin K and Depressive Symptoms in Late Adulthood: A Cross-Sectional Analysis from a Large Cohort Study, Nutrients 11(4):787, doi: 10.3390/nu11040787
- Ferland G (2013) Vitamin K and Brain Function, Semin Thromb Hemost 39(08): 849-855, doi: 10.1055/s-0033-1357481
- Chouet J, Ferland G, Féart C, Rolland Y, Presse N, Boucher K, Barberger-Gateau P, Beauchet O, Annweiler C (2015) Dietary Vitamin K Intake Is Associated with Cognition and Behaviour among Geriatric Patients: The CLIP Study, Nutrients 7(8): 6739–6750. doi:10.3390/nu7085306
- Tamadon-Nejad S, Ouliass B, Rochford J, Ferland G (2018) Vitamin K Deficiency Induced by Warfarin Is Associated With Cognitive and Behavioral Perturbations, and Alterations in Brain Sphingolipids in Rats, Front. Aging Neurosci. 10:213, doi: 10.3389/fnagi.2018.00213
- Kiely A, Ferland G, Ouliass B, O’Toole PW, Purtill H, O’Connor EM (2018) Vitamin K status and inflammation are associated with cognition in older Irish adults, Nutritional Neuroscience, doi: 10.1080/1028415X.2018.1536411