Biotin is often recommended for strengthening hair and nails.nutraMetrix Isotonix?? Activated B-ComplexMethylcobalamin (Vitamin B12) 120 mcg Vitamin B12 (cobalamin) is a bacterial product naturally found in animal products, especially organ meats, such as liver, with small amounts derived from peanuts and fermented soy products, such as miso and tempeh.