Vitamin K (menaquinone) has long been known as a vital hero in blood clotting and maintaining strong bones.

However, recent research reveals a more important role: its potential in neuroprotection and delaying cognitive decline and dementia, including Alzheimer’s disease. Vitamin K acts as a silent guardian enhancing the brain’s internal defenses at the cellular and vascular levels.

How Does It Protect the Brain? Evidence and Mechanisms

Studies confirm a strong relationship between vitamin K levels and protection against cognitive decline. A post-mortem brain tissue analysis showed that individuals with higher amounts of menaquinone-4 (MK-4), the most active form in the brain, were less likely to suffer from dementia and cognitive deterioration.

Higher MK-4 levels were also linked to reduced accumulation of harmful proteins associated with Alzheimer’s disease.

Research also showed that those who consume sufficient amounts of this vitamin have lower levels of nerve damage markers, such as decreased light neurofilament chain, a protein considered a vital indicator of neuronal health. These studies indicated that positive effects stabilize at a daily dose of about 200 micrograms.

The Brain’s Multifaceted Protection, From Blood Vessels to Neurons:

• First, it is essential to maintain flexible and healthy arteries by preventing calcium buildup and “rust” formation inside small blood vessels in the brain, ensuring efficient blood flow and preserving oxygen and nutrients.
• Second, it protects mitochondria (the energy stations inside neurons) from damage caused by stress and aging, acting as an antioxidant that reduces free radical damage, thus slowing neurological decline.

Diet and Consumption: Where to Find This Vitamin?

Since vitamin K is fat-soluble, the body needs a fat source to absorb it effectively. It is recommended to consume it with a meal containing healthy fats like olive oil or nuts. Vitamin K2 differs from the K1 form found in leafy greens; it is mainly produced by bacterial fermentation and comes from specific sources:

• The richest source: Japanese natto, a fermented soybean dish, is the richest source of vitamin K2.
• Dairy products and cheeses: Aged cheeses like Gouda and Emmental contain excellent amounts, and full-fat dairy products such as butter and ghee from grass-fed animals provide good quantities.
• Animal sources: Egg yolks and organ meats, especially beef liver, provide the highly effective MK-4 form efficiently absorbed by the brain.

Who Should Focus on Vitamin K2 and Who Should Be Cautious?

Increasing vitamin K2 intake is a beneficial preventive step for most people, but it should be especially emphasized for the elderly to prevent cognitive decline and osteoporosis, as well as those genetically predisposed to dementia or Alzheimer’s.

Important Safety Warning: Vitamin K is very safe for daily consumption except for one group: people taking blood-thinning medications that counteract vitamin K. These individuals must maintain a very consistent amount of vitamin K in their diet and consult their doctor before making any significant dietary or supplement changes, as sudden changes may affect medication effectiveness and increase the risk of clotting or bleeding.