Could my "growing pains" as an adult be caused by a vitamin deficiency?

Probably not.: The term "growing pains" is very nonspecific and medically has little meaning. I assume you are referring to some sort of musculoskeletal or joint pain. Vitamin deficiencies are rare in the us, unless you have underlying disease, and specific ones are associated with specific syndromes, e.g.Niacin deficiency is the cause a syndrome called pellagra i know of no deficiency syndrome that causes pain.