Taking too many vitamins and supplements can be dangerous and even life-threatening. People with severe overdoses may experience coma, low blood pressure, liver failure, lung injury, and death. Vitamin A, C, and zinc can cause nausea, diarrhea, stomach cramps, hair loss, gastrointestinal disorders, fatigue, and mild nerve damage. Excess selenium can even lead to bone loss.
Vitamin A is a fat-soluble nutrient that occurs naturally in many foods. An overdose of this vitamin can cause confusion, hair loss, liver damage, and an increased risk of death and lung-related problems in people who have a history of smoking, especially in women who smoke. Combining several vitamins or taking doses higher than recommended may increase the risk of harm. Water-soluble vitamins can cause adverse effects when taken in excess, some of which can be dangerous.
Megadoses of some water-soluble vitamins can cause potentially dangerous side effects. It's important to remember that just because vitamins and supplements are safe in moderation doesn't mean that more is better. Taking too many supplements can lead to serious health risks such as organ damage, coma, and even death. It's important to consult with a doctor before taking any supplements to ensure that they are safe for you.