The Real Reason You Feel Tired After Taking Vitamins

If you're committed to your health, taking vitamins might be part of your daily routine. Vitamins are essential substances needed for proper cell function, growth, and development (via MedlinePlus). Between multivitamins, minerals, and herbs, there are so many options to choose from. Generally speaking, vitamins can be grouped into two different categories: fat-soluble and water-soluble. Fat-soluble vitamins (A, D, E, and K) are stored in fatty tissue, liver, and muscles. Additionally, dietary fat helps the body more easily absorb these vitamins. On the other hand, water-soluble vitamins (like vitamins B and C) can't be stored in the body and need to be taken often to maintain healthy levels.

Minerals can also be supplemented, like calcium, magnesium, and potassium (via Harvard T.H. Chan School of Public Health). The National Academy of Medicine sets Dietary Reference Intakes (DRIs) for vitamins and minerals to guide individuals on recommended daily doses. While it's reasonable to assume we'll feel better and more energized if we take our vitamins at the recommended doses, we actually may end up feeling sub-optimal and fatigued if we take too much.

While adequate amounts of vitamins are recommended for our health, too many vitamins can lead to unwanted health outcomes. Some vitamins can be harmful to our health in doses that are too large and cause fatigue, according to Livestrong. But worse than that, it can lead to more severe adverse effects like confusion, weakness, increased urination, tooth staining, and uneven heart rate (via Drugs.com). 

In addition to fatigue, taking a multivitamin on an empty stomach can also lead to nausea, upset stomach, and diarrhea, making it difficult to perform daily tasks (via Cleveland Clinic). Vitamins and supplements can also aggravate gastrointestinal disorders such as irritable bowel syndrome and gastritis.

While supplements can help boost your nutritional intake, eating a balanced diet with a variety of foods like shellfish, legumes, dairy products, and seeds is the best way to get enough daily vitamins without the risk of side effects, according to Cleveland Clinic.