One of my patients is always searching for the fountain of youth. He invariably shows up for his clinic appointment with a large bag full of various vitamins and supplements. The bag will also include the latest fad in “cleansers” and “de-toxifiers” that are guaranteed to rejuvenate, promote longevity and invigorate body and soul. These products are often quite expensive but have little or no proven benefits for one’s health.

The major exceptions are vitamins. But, vitamins are important in appropriate doses and for certain physiologic and cellular functions. They are not the panacea that is often promoted by social media or a Google search.

Vitamins are actually micronutrients that we get thorough our diet. There are two general classes of vitamins: Fat-soluble and water-soluble.

Fat-soluble vitamins include Vitamin A which is important for night vision; Vitamin D which is important for bone growth and other vital functions; Vitamin E which is important for blood production as well as nerve and muscle health; and, Vitamin K which is important in blood clotting. The Food and Drug Administration has published the recommended daily allowance for all vitamins and nutrients.

Water soluble vitamins include Vitamin C (or ascorbic acid) which is important for collagen production, wound healing and oral health. The other group of water-soluble vitamins includes the various B complex vitamins which are important in cellular processes, glucose metabolism, skin and nerve health and blood production.

Our bodies can be harmed if we have too few vitamins and importantly if we take too many. The Food and Drug Administration has published the recommended daily allowance for all vitamins and nutrients.

How did we discover vitamins? Let’s look at vitamin C.

Steven Bown’s excellent book, “Scurvy: How a Surgeon, a Mariner, and a Gentleman Solved the Greatest Medical Mystery of the Age of Sail,” provides a fascinating history of the importance of a disease in military history. I recommend this book for anyone interested in the history of medicine or naval history.

In his book, Bown details the historical importance of vitamin C to the British navy. Scurvy is a disease that is caused by a deficiency of vitamin C. Sailors would develop open sores, old battle wounds would re-open, and their gums would start bleeding and subsequent dental loss would occur. The sailors would also become weak and eventually succumb to the disease. (More men would die of scurvy than from battle at sea!)

Eventually, though trial and much error (and medical establishment resistance) the British discovered that having the sailors eat citrus fruits would prevent scurvy (thus, the term “limeys”). It wasn’t until the 20th century that vitamin C was finally synthesized. Vitamin C’s chemical name is ascorbic acid, which actually means “anti-scurvy” acid.

Vitamins with antioxidant properties have also been touted as having a role in preventing heart disease and cancer. In 2013, The American College of Physicians published the results of one large study on vitamins and heart attacks, one large study on vitamins and cognitive function and a comprehensive review of all published literature on cancer and vitamins. No conclusive benefit of vitamin supplementation was found in any of the studies. An accompanying editorial was entitled; “Enough is Enough: Stop Wasting Money on Vitamin and Mineral Supplements.”

What should I recommend to patient as he searches for the fabled fountain of youth? Stop buying those expensive pills, eat a balanced plant-based diet and exercise moderately.

Dr. Alan Jackson is a cardiologist and chief medical officer at Roseland Community Hospital and clinical assistant professor of medicine at the University of Illinois Chicago. He also is a member of the Sun-Times board of directors.