Vitamin K1 (phylloquinone) is mainly found in green leafy vegetables and is primarily associated with diet. Vitamin K2 (menaquinones) is present in fermented products and animal foods. K2 has several subtypes, with menaquinone-7 (MK-7) being a widely used variant in supplements due to its longer presence in the body.

Menaquinone-7 is a specific form of vitamin K2 obtained through fermentation (e.g. from natto). This form is often chosen for supplements because of its stability and the possibility of a low dosage per capsule.

Vitamin D2 (ergocalciferol) is of plant origin, while vitamin D3 (cholecalciferol) usually comes from animal sources, such as wool fat (lanolin).

Both vitamin D and K are fat-soluble. An oil base, such as MCT oil, ensures a good distribution of the fat-soluble substances in the capsule and is common in this type of supplement.

A meal usually contains fats, which can support the absorption of fat-soluble vitamins such as D3 and K2. That's why it's often advised to take fat-soluble supplements during or after a meal with some fat.