I’ve been taking 50 mg zinc picolinate for over a year — no problems. I get K2 from egg yokes.
From the web: "Even moderately high intakes of zinc of about 60 milligrams per day for up to 10 weeks have been reported to reduce a copper-containing enzyme (a marker of copper status). Zinc supplements also have the potential to interact with several types of medications (such as antibiotics and diuretics). As such, be sure to discuss your zinc intake with your healthcare provider.”