What Causes Muscle Spasms And Pain In Back/arm While On Multivitamin?

My daughter is has been taking a multi vitamin for over a year and 4 months ago began suffering muscle spasms and pain in her back, arm neck and legs. She has been to a neurologist, and an rheumatoid doctor. After many test they only found low vitamin D. She has been taking it for a month and does not seem to e getting better. She says worse. Could she be allergic to something in the multi vitamin?