I recommend 고려은단 Vitamin C 1000.

Since it consists of two small pills, it is easy to swallow for people like me who cannot take large pills. It contains antioxidant vitamin C and bone health vitamin D, which is great. Vitamin C is an essential nutrient that must be taken regularly. People who have limited outdoor activities should also take vitamin D properly for bone health. I recommend the Koryo Eundan Vitamin C 1000, which contains both at once.