<p>Vitamin D Ultra 10K is our highest potency vitamin D product, providing 10,000 IU of vitamin D per serving, and is intended for situations where more aggressive vitamin D repletion is required. Our lower dosage option, Vitamin D Synergy (2,000 IU/serving), should be considered for maintaining optimal blood levels of vitamin D for long-term supplementation. Vitamin D Ultra 10K also includes 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. Vitamins D and K are essential for optimal bone and arterial health and for maintaining the immune system in proper balance. Made with non-GMO ingredients.</p>