What does red hair mean?

1. Because iron is an essential trace element to form black hair, when suffering from iron deficiency anemia, hair can change from black to brown, which is equivalent to hair malnutrition. 2. Nutritional deficiencies observed in animal experiments include long-term deficiency of trace elements such as protein, vitamin A, B 1, B2, B6, folic acid, pantothenic acid or copper and zinc, which can make rat hair white, and human hair sparse, sparse, dry and hypopigmentation. 3. The color of hair is related to heredity, which can be explained by checking the trace elements in hair. Yellow hair is black and contains trace amounts of copper and iron; Indian hair is reddish brown and contains copper and cobalt. The formation of red hair is related to protein, iron and "hair iron pigment" loosened by chromophore different from melanin.