@tillymack I think they are two different types of calcium so that's why I take both. New Chapter is sourced from algae and AI Assist says: "Algae calcium, specifically derived from red algae such as Lithothamnion, is a plant-based form of calcium that is highly absorbable and contains additional trace minerals beneficial for bone health. This type of calcium is considered superior to traditional rock-based calcium supplements."

Citrical is calcium citrate. Both contain Vitamin D but New Chapter also contains some vitamin K. If I were to choose just one, I'd go with New Chapter.