Methotrexate interferes with the metabolism of

Methotrexate interferes with the metabolism of Folate. Methotrexate is an antineoplastic anti-metabolite and enters cells via the reduced folate carrier, which also transports the naturally occurring reduced folates, including the most common form found in food, 5-methyltetrahydrofolate. MTX causes the body to get rid of more folate as waste than usual which causes a folate deficiency. 

Iwould say silver and gold