People with hypothyroidism may want to consider minimizing their intake of gluten, a protein found in foods processed from wheat, barley, rye, and other grains, says Ruth Frechman, RDN, a dietitian and nutritionist in the Los Angeles area and a spokesperson for the Academy of Nutrition and Dietetics.
Yellow Nails. One of the most common causes of yellow nails is a fungal infection. As the infection worsens, the nail bed may retract, and nails may thicken and crumble. In rare cases, yellow nails can indicate a more serious condition such as severe thyroid disease, lung disease, diabetes or psoriasis. Swipe to advance.
Quick Answer. The main cause of a purple tinge in fingernails is low oxygen levels in the blood. This can be caused by poor circulation, as well as habits that inhibit oxygen absorption such as smoking. A single fingernail may also become purple if it has been injured, indicating a bruise underneath the nail.