Intramuscular B-12 injections are used to correct a common B-12 deficiency. This deficiency can affect people of all ages, not just the elderly. Symptoms may include fatigue, poor memory, poor balance, nervous disorders, anemia, and neurological or immune disorders. A patient with a blood test showing the B-12 level within the normal range of 200-900 may in fact be experiencing some symptoms if their B-12 level is below 600. Integrated medicine considers what is traditionally a "normal"  level may not be "optimal". Studies have shown that B-12 levels below 600 are clinically low and reflect a deficiency of B-12 in the cells and tissues of the body. Vegetarians may show a low B-12 level since most dietary sources of B-12 is in meats. For those with a B-12 deficiency (below 600), who are not vegetarians, their problem is poor absorption, not inadequate dietary intake. The most expedient way to correct this is with a series of B-12 muscular injections, which is better stored by the liver, followed by supplements of sub-lingual B-12.

Benefits of intramuscular B-12 injections are: quicker uptake of the vitamin, better storage in the liver, increased energy, better memory recall, and improved mood and ability to handle stress.