Are there any vitamins that should not be mixed together, either because of negative reactions, or just reduced efficiency?
I find it easier to take all of my vitamin supplements at once. I have an alarm set on my phone to take them or else I will forget.
I currently take: a multi, Vit D, magnesium, calcium and a pro-biotic.
So my question is, would any of these affect each other?
Also, are there any other vitamins that people may take that may affect each other?
I think you need to take calcium and magnesium at separate times. They sort of counteract each other. I would take the Vit D and calcium in the morning and magnesium & probiotic at night.
Don't bother with the multi.
Some vitamins are fat soluble (D and others in your multi), so you should take them with fat.
Personally I just take all my supplements at once with my evening meal. Why? Because that way I know I'm not going to forget that I took them earlier in the day and accidentally double up on them, and besides, I often only eat one meal per day.