I would seriously doubt that it matters what time of day. I do know that in order to absorb as much of the nutrients as possible, you need to consume the vitamins/supplements with at least a small amount of food and follow by frink 8-16 oz of water.
I'd guess sometime in the morning.
***General rule of thumb is to take supplements with food in your stomach, avoid taking them on an empty stomach, unless dircted otherwise.
I just wanted to add that it depends what nutrient you are taking. Iron, for example, is not absorbed as well with high fiber food, coffe or tea. These foods can reduce the absorption of iron and iron is a poorly absorbed nutrient. However, if iron is taken with vitamin C or orange juice, the absorption increases. So if you're taking iron, take it in the morning with orange juice and wait to drink your coffee or tea.
I take mine in the morning. Some brands you can take two per day, one in the morning and one at night so you have vitamin release all day and night long. Your body needs its vitamins even when you sleep.
Answer
The best time to take vitamins (multi) would be after your breakfast.The best time to take antioxidants and minerals like chromium would be immediately after workout.
Minerals like zinc and magnesium get absorbed better in nite before bed
All protein and creatine supplement get absorbed best immediately after workouts.