Calcium and magnesium are minerals that are known to be essential for bone health.* Along with these two important minerals NOW? Cal-Mag DK Caps provide vitamins D and K.* Vitamin D-3 a fat soluble vitamin has been shown to play a critical role in bone metabolism as well as in the absorption of calcium and magnesium in the intestine.* Vitamin K-2 is a nutrient that further supports bone health through its participation in healthy bone calcification.* Natural color variation may occur in this product. Take 2 capsules twice daily with food.