Pollen can be derived from different flowering and this means that two jars pollen can be very different. Thus, nutrients of each pollen are different. The protein content in pollen has range from 7,5 to 35 %. It contains usually less than 5% fat but also sugars, vitamins, starch and inorganic salts.
In an excellent review / survey (Schmidt and Buchmann, 1992) in which pollen was compared with other foods (beef, fried chicken, baked beans, wholemeal bread, apples, raw vegetables and tomatoes) for the average protein, fat, vitamins and minerals content, pollen was richer in most ingredients (when you compare the content of by weight or calories of these foods).
Pollen in comparison (protein and minerals) with beef and beans have more than ten times more thiamin, riboflavin and niacin.
But do not forget that the pollen is usually consumed in such small quantities that the daily requirement of vitamins, proteins and minerals may not be obtained through the consumption of pollen only. However, pollen may be a significant source of essential nutrients as a dietary supplement when it is insufficient. (FAO, 1996)