Vitamin D Supreme provides a clinically useful dose of vitamin D3, 5000 IU per veggie cap, and vitamin K in both K1 and the MK-7 form of K2, which is highly bioavailable. Both of these forms of Vitamin K are important to our health: Vitamin K1 (the naturally occurring form of vitamin K in vegetables) and Vitamin K2 as MK-7, which is a product of soy fermentation (free of soy allergens) and has the special property of metabolizing slowly throughout the day.This formula contains higher therapeutic doses than Vitamin D Synergy for situations where more aggressive repletion is required. Most holistically oriented health care practitioners are aiming for vitamin D blood levels of between 50 - 100 ng/mL as optimal. Many patients will require a higher dose of vitamin D as found in Vitamin D Supreme to achieve this. Vitamin D Synergy, our 2000 IU lower dose product, should be considered for maintaining optimal blood levels of vitamin D for long-term supplementation in patients that are exposed to adequate sunlight. Vitamins D and K are essential for optimal bone and arterial health and for maintaining the immune system in proper balance. The amount of vitamin D and K in this formula may correct the deficiencies of a majority of patients that do not get adequate sun exposure and/or dietary sources of these vitamins.We now know how important Vitamin K is for directing the transport of calcium into bone and teeth for optimal strength. Increasing the amount of vitamin D, via supplementation, in the presence of inadequate levels of vitamin K, can increase the risk of calcium deposition in arteries and soft tissue and have a very negative effect on artery elasticity. This is due to their interaction in the use of MGP, Matrix Gla Protein, which is a strong inhibitor of arterial calcification. The expression of MGP is vitamin D dependent and the gamma-carboxylation step, making it active, is vitamin K dependent. Together, D and K make a great team.