How should vitamin C tablets be stored after opening to extend shelf life?

Sealed storage
After opening the vitamin C tablets should first pay attention to sealing. You can use the seal lid or strip that came with the original package to ensure that the container is tightly closed. This is because the air contains oxygen, and vitamin C has strong reducibility and is easy to be oxidized. If not sealed properly, vitamin C tablets will be in constant contact with oxygen in the air, accelerating their oxidation process. For example, when vitamin C tablets are exposed to air, they oxidize much faster than if they were sealed, potentially making them less effective quickly.
Store away from light
Keep vitamin C tablets away from light. Light, especially ultraviolet light, causes vitamin C to break down. Keep vitamin C tablets in an opaque pill box, drawer, or cabinet. For example, put it in a glass bottle with a dark coating, or wrap the original bottle in a black bag, which effectively blocks light. If vitamin C tablets are placed in direct sunlight windowsills or transparent glass containers for a long time, it will accelerate their deterioration, and the color of the tablets may turn yellow, which is a sign that vitamin C is oxidized.
Control temperature
Vitamin C tablets are suitable for storage in the shade, and the ideal temperature is below 20 ° C. Excessive temperature will speed up the breakdown rate of vitamin C. Therefore, do not put it near a heat source (such as heating, stove), and do not put it in a place where the temperature is easy to rise, such as the interior of a car (the interior temperature of a car will rise sharply under sunlight). You can choose to put vitamin C tablets in a cabinet where the temperature is more stable, such as a cabinet in the bedroom or living room.
Control humidity
Keeping the environment dry is also important. High humidity may cause vitamin C tablets to deliquescent, making them soft, sticky and even moldy. Indoor relative humidity is best controlled at 40%-60%. In the humid season (such as the plum rain season in the south), desiccant (such as silica gel desiccant) can be used to absorb the surrounding moisture. Place the desiccant near the container containing the vitamin C tablets, but be careful not to let the desiccant come into direct contact with the vitamin C tablets to avoid contamination.