Dietary Supplement. New Look. Same Great Product! #1 Doctor Recommended Brand. Take Once Daily. 1200mg of Calcium & 1000IU of Vitamin D3. Slowly & Continuously Releases Calcium for Efficient Absorption. What is Citracal® Slo-Cal™ Technology*? Slo-Cal Technology is a breakthrough, patent-pending technology that has been specifically developed and researched to provide efficient calcium absorption in just one daily dose. Citracal Slow Release 1200 contains 1200mg of calcium plus 1000IU of vitamin D3 in o.