Is there anything other than fugus that turns the tip of both big toenails to turn yellow?any vitamine defiiencies or anything?

Multiple Etiology: Excessive nail polish use or fungal infections are the most likely causes of yellow toenails. However, yellow toenails can sometimes be sign of a more serious underlying condition.Part of the toenail turning yellow can be a natural consequence of Aging. Other causes which needs Rx--Infection--Yellow nail syndrome ( cause not known in >50yrs.) and host of other condition such as TB,, Psoriasis, DM.