Intramuscular injections, such as Vitamin B12 and Vitamin D, are used to treat deficiencies, and allow for quicker and effective absorption into the body compared to subcutaneous and intradermal injections, and oral medications. The administration technique is simple and accessible. Shots that are delivered directly into the muscle avoid gastric factors and are a preferred method for those who have difficulty tolerating oral supplements or are not consistent with a supplementation regimen. Common injection sites include the deltoid muscle (upper arm), vastus lateralis (thigh), and dorsogluteal muscle (buttocks).