Are jamieson b complex 100 mg too much?

For what condition? Jamieson's b complex 100 mg is a timed-release product. B vitamins are also water-soluble, so that any excess your body does not need will be excreted. Taking vitamin b6 (pyridoxine) at 1-6 grams (not milligrams as in this preparation) per day over many months can cause a sensory neuropathy. For most people, the 50mg b complex would be enough -- if you have poor diet & stress, maybe need more.