Patient Typing Fatigue, achiness, hair loss, muscle weakness, bad immune response Brain Support/ Cognitive Function Bone Strength Elderly Patients How to Dose 1 capsule a day with meal. How does Sun Power work? Vitamin K2 with D3 includes 45 mcg of MenaQ7® PRO, the most widely studied form of vitamin K2 as MK-7, and 5,000 IU of vitamin D3 per capsule for optimal absorption and use by the body. Vitamin K occurs in two main forms: K1 (phylloquinone), derived from foods such as green leafy vegetables and K2 (menaquinone), which is a group of related compounds differentiated by their side chains. Numerous studies have shown that vitamin K2 as MK-7 is the more bioavailable form of nutrient 7 and more powerfully influences bone building than K1. There are two forms of vitamin K2 commonly used in supplements: MK-4 and MK-7 The MK-7 form has been shown to have six times the activity of MK-4 in the blood. MK-7 has also been found to remain in the blood approximately nine times as long as the MK-4 (eight hours versus 72 hours), making it the optimal form of K2 for health.