What does buffered mean?
The vitamin C is bound to a mineral, usually calcium or magnesium, which makes it non-acidic and gentler on the stomach.
Is buffered vitamin C better absorbed?
The main difference is that it is gentler rather than stronger. If plain vitamin C suits you, it is cheaper and does the same job.
Should I split the dose?
Splitting it across the day is generally more useful than one large amount, since vitamin C is water soluble and not stored.
Does it count towards my calcium intake?
Buffered forms contain minerals as part of the compound, so check against anything else you take.