21st Century, Vitamin D3 Ultra Strength, 10,000 IU, 110 Tablets. Description Vitamin D3 is essential for absorption of Calcium and necessary support for healthy bones, teeth and immune system. Vitamin D3 also supports breast and colon health. Suggested Use As a dietary supplement, adults take one (1) tablet daily, preferably with a meal for maximum results or as directed by your healthcare provider. Do not exceed recommended dosage. Individual results may vary.