My Dad Is 92 Years Old. The Past Two Days

My dad is 92 years old. The past two days he has been very dizzy. I usually take my mom and dad to Sunday brunch. Today he said he was much too dizzy to go to brunch. He was worried that he might fall down because of dizziness. He claims he is suffering from vitamin poisoning. He said it is not that his age is a factor. I believe he may have suffered a mini stroke. Please advise.