Amino acids: are obtained from pollen only, because honey bees do not have any other sources of protein. Brood rearing decreases and workers live shorter-than-normal lives without protein. Nutritional value of pollen may be defined more accurately by the amino acid composition than by protein content. The amino acids in greatest need are isoleucine 4.0%, valine 4.0%, and leucine 4.5%; intermediate needs are arginine 3.0%, lysine 3.0%, threonine 3.0%, and phenylalanine 1.5%; lowest needs are methionine 1.5%, tryptophan 1.0%, histidine 1.5%. Pollen usually contains 6% to 28% protein. These 10 amino acids must be balanced for bees to fully use what is available in the pollen (see illustration: Amino Acids Line Graph).
LIPIDS: Honey bees obtain a sterol, 24-methylene cholesterol, from pollen because of their inability to synthesize it directly. Sterol is the precursor for the molting hormone, which regulates growth required at the time of each molt. Winter colony bees are physiologically different from their sister summer bees. These winter bees use lipids for developing good fat bodies in the dorsal and ventral layers to survive the winter, and to be able to sustain the provision of brood food during the coming spring should pollen sources be scarce, or bad weather prevent foraging.
VITAMINS: Nurse bees are thought to need vitamin B complex for brood rearing: thiamine, riboflavin, nicotinamide, pyridoxine, pantothenic acid, folic acid, and biotin. Ascorbic acid (vitamin C) also seems essential for brood rearing.

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