Vision
Gene transcription
Immune function
Embryonic development and reproduction
Bone metabolism
Haematopoiesis
Skin health
Reducing risk of heart disease
Antioxidant Activity

The B vitamins often work together to deliver a number of health benefits to the body. B vitamins have been shown to:

Support and increase the rate of metabolism
Maintain healthy skin and muscle tone
Enhance immune and nervous system function
Promote cell growth and division — including that of the red blood cells that help prevent anemia.
Reduce the risk of pancreatic cancer, one of the most lethal forms of cancer[4], when consumed in food, but not when ingested in vitamin tablet form.[5][6]
Together, they also help combat the symptoms and causes of stress, depression, and cardiovascular disease.

All B vitamins are water soluble, and are dispersed throughout the body. Most of the B vitamins must be replenished daily, since any excess is excreted in the urine.[7] A six year cobalamin store can be found in the liver, despite its water soluble nature immunomodulation
cancer prevention and recovery
cardiovascular disease prevention
Role in all-cause mortality

plays a role in immune function , protein synthesis wound healing, DNA synthesis, and cell divisionZinc also supports normal growth and development during pregnancy, childhood, and adolescence and is required for proper sense of taste and smell. A daily intake of zinc is required to maintain a steady state because the body has no specialized zinc storage system
References :
http://en.wikipedia.org/wiki/Vitamin_A
http://en.wikipedia.org/wiki/B_vitamins#Health_benefits
http://en.wikipedia.org/wiki/Vitamin_D
http://ods.od.nih.gov/FactSheets/Zinc.asp