Vitamins. A good multivitamin is a good idea. It's like an insurance policy for when we don't eat right, don't sleep well, or are especially stressed. Go to a good store or get some guidance because the popular brands are typically very week and not helpful. Poor food quality and soil depletion lowers nutritional value w/food today. Ask your doctor for lab test to determine if specific vits are low. .
The Best Time. Stop taking worthless multivitamins. That is your BEST move. If you have a specific vitamin deficiency which is definitely proven with tests, then take that specific vitamin. Otherwise, save your money and get a gym membership. Exercise has proven health benefits. Multivitamins do not and may hurt you.
Multivitamins. Multivitamins are best taken with food in the morning because they tend to be stimulating.