Will graphite cause lead poisoning

No, it cannot.

Graphite is just carbon, which is an essential component of life itself. There is no known illness or notable harm caused by ingesting small amount of carbon. Just as it was mentioned above that charcoal is sometimes used to absorb some poisons that may have gotten into your stomach, charcoal caplets are also used to treat indigestion by absorbing some of the fats that are making your feel sick.