Many youth-obsessed older people take dietary supplements in an effort to turn back the hands of time. Biotin is one of the supplements people over 40 purchase to hold off the hair loss, aging skin and nails that are among the unwelcome changes of aging.

Biotin is unlikely to make you look any younger, even taken in large quantities; but it may well prevent a doctor from diagnosing a heart attack if you have one, a study published in JAMA, the Journal of the American Medical Association finds.

A member of the family of B vitamins, biotin is often included in multivitamins, and at the low doses present there, it does not pose a risk. However, when taken at high doses, defined as one milligram a day or more, it can interfere with the results of some important blood tests.

Little has been known about the popularity of high-dose biotin use, so researchers at the University of Minnesota looked into the issue by analyzing information gathered in the U.S. National Health and Nutrition Examination Survey, a periodic survey of Americans about their health and lifestyle habits.

Should you be rushed to the emergency room with a suspected heart attack, the ER doctor will need to know if you take high doses of biotin.

In 1999-2000, just 0.1 percent of Americans used a biotin supplement. Fast forward to 2016, that number had jumped 30 percent, with three percent of adults in the U.S. taking biotin. Women were more likely to take it than men, with over seven percent saying they took at least one milligram per day — over 30 times the recommended intake — and two percent taking five milligrams or more per day — 150 times the recommended daily intake.

In 2017, the U.S. Food and Drug Administration issued a safety alert on the use of high doses of biotin saying that it could "significantly interfere with certain lab tests and cause incorrect test results, which may go undetected."

An example of such an interference is with a blood test for a troponin level. Troponin is a protein found in the heart. When the heart is damaged by a heart attack, troponin is released into the blood. The higher the level of troponin in the blood, the greater the damage to the heart.

High doses of biotin can cause troponin levels to be deceivingly low, which can interfere with a correct diagnosis of a heart attack. This is especially concerning for older adults who have an increased risk of heart attack, especially if they also have high blood pressure or diabetes, and are also taking biotin supplements.

A biotin deficiency can cause hair loss, skin rash and brittle nails, so it’s understandable that aging women and men experiencing these conditions would be drawn to something advertised to reverse these changes. However, a biotin deficiency is rare, according to the U.S. National Institutes of Health, and there is little evidence that taking biotin will improve the appearance of skin, hair or nails.

A healthy diet is always a better source of nutrients than dietary supplements. Foods are packages of carbohydrates, protein, fats, vitamins, minerals, fiber and phytochemicals that work together to contribute to your good health — and appearance.

The recommended amount of biotin is 30 micrograms a day, something a healthy diet can easily provide. Animal foods such as beef liver, chicken liver, eggs and salmon contain high amounts of biotin, but dairy foods are not a very good source. Plant foods like sweet potatoes, spinach and broccoli, as well as many types of nuts and seeds also contain biotin.

While we all wish there was a fountain of youth, biotin does not seem to be it. Yet if you choose to take high doses of this B vitamin, tell your doctor because it can interfere with the results of other lab tests, too. Should you be rushed to the emergency room with a suspected heart attack, the ER doctor will need to know that you take high doses of biotin.