Multivitamins are collections of vitamins, minerals and other beneficial dietary supplements. They are meant to be paired with a healthy diet and provide the human body with necessary supplements that may not always be available through a regular diet. The regular use of multivitamins can prevent many common conditions.

Multivitamins have also been proven to strengthen the immune system, therefore reducing the risk of infectious diseases, especially among the elderly. Because the ability to absorb B vitamins decreases with age, a multi-vitamin supplement that includes B vitamins can be highly beneficial, strengthening the immune system by up to 60% and reduce the risk of contracting infections such as foot ulcers and urinary tract infections.

Regular use of multivitamins also prevents fractures, especially among post-menopausal women and the elderly. Research has found that calcium (which is found in virtually every over-the-counter multivitamin) may improve bone density in post-menopausal women, reducing the risk of vertebral fractures. Paired with Vitamin D, calcium has also been proven to reduce the risk of hip fractures among the elderly. The regular use of these vitamins could reduce the number of hip fractures in the United States by as many as 50,000 a year.

Vitamin or mineral deficiencies can also lead to many major effects, all of which can be avoided through the regular use of a multivitamin. For example, B12 deficiency can cause anemia, confusion, loss of appetite, depression, fatigue, hair loss, and constipation. Vitamin C is especially important, and a deficiency in this vitamin can cause bleeding gums, nosebleeds, slow healing of wounds, tooth decay, scurvy, hemorrhages, and impaired digestion.