Vitamin B7 Biotin heals one important deficiency symptom, the inability of the body to absorb the other B Vitamins. It also helps break down the accumulation of fatty acids in the body by assisting in their metabolism. Biotin is also, along with Vitamins A, B2 and B6, great for helping to heal eczema and prevent hair loss. Another benefit is that is strengthens fingernails. Signs of Biotin deficiency include dry, grayish skin, hair loss, nausea, vomiting, muscle pain, loss of appetite, a pale, smooth tongue, and fatigue. People can become Biotin deficient through long term use of antibiotics or by eating raw egg whites, which contain avidin, a protein that blocks the body's absorption of Biotin.