Sentinel B-12 is a dietary supplement containing 500 micrograms of Vitamin B-12 per tablet, with 100 tablets per bottle. This essential nutrient supports red blood cell formation, DNA synthesis, energy metabolism, and proper nervous system function. Vitamin B-12 is particularly important for maintaining healthy energy levels and cognitive function. The supplement comes in tablet form packaged in a dark amber bottle to protect from light degradation. This dosage (500 mcg) is commonly recommended for those with B-12 deficiency, vegetarians/vegans, older adults, or individuals with absorption issues. As with any supplement, consult a healthcare provider before use.