Can be taken with or without food. No.1 doctor & pharmacist (Pharmacy Times survey 2015) recommended calcium brand. Defy bone aging with Critical calcium and a high level of vitamin D3. Adequate calcium and vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis. Critical Maximum is made with calcium citrate, a different kind of calcium: Highly soluble, easily absorbed. Can be taken with or without food. Gentle on your digestive system.