I suggest using natural ones. I'm eating at Yangshengtang. One tablet a day is actually very safe. If you are not at ease, you can take it every other day.
Although VC will not accumulate in the body, once it is taken in large quantities for a long time, it will induce sepsis (is it scary? Don't worry, the amount you eat will never:)
But VC had better take complementary food and eat more peaches, strawberries and oranges.