It is best not to use a fluoridated toothpaste until they reach the age of 3. If used earlier than that it is hard to make sure they are rinsing the toothpaste out and not swallowing it.
You should always supervise the brushing of your toddler’s teeth and only provide them with a pea-size amount of toothpaste. Try to make sure that they are not swallowing any excess amount.