It depends upon where you go to school and the teacher. For years, the nutritional calorie. was actually the kilocalorie (1000 calories) but everyone referred to it as the calorie. Those people usually then differentiated between the BIG calorie (spelled with a capital Calorie) and the small calorie (spelled with a small c). There are a number of universities and colleges around the country (I don't know about outside the US) that are teaching the calorie as it is defined in the dictionary and text books and they refer to the nutritional calorie as the kilocalorie. This is a relatively new practice but I suspect that eventually everyone will go to the one standard.
