Human hair are made up of made up of keratin, which is a tough protein. Each strand has three layers: the cuticle (outer layer), cortex (middle, gives strength and colour), and medulla (inner core). Hair also contains lipids, water, and trace minerals. And so, a deficiency of protein, Vitamin D, B12, or zinc can weaken one’s hair structure. A poor diet or crash dieting often reflects in one’s dull hair and excessive shedding.
