Is it ok for children to have vitamin c chewable tablets? each tablet has 500mg of vitamin c.

Depends: Depends how old they are. I won't recommend for toddlers to avoid choking.

Better if buffered: Vitamin c is beneficial for children & adults 500 mg they are like candy that's good for you! however, there is the potential for chewable vit c tablets to erode dental enamel due to their acidity. This risk is greatly reduced if you choose a buffered c tablet with sodium or calcium ascorbate instead of ascorbic acid. If what you have is not buffered, brush teeth after using & choose buffered next!

Be careful: Vitamin c - also known as Ascorbic Acid can damage teeth.