Your body may give you clues when it isn't getting everything it needs. Unexplained fatigue, hair loss, brittle nails, dry skin and even bleeding gums can sometimes be associated with nutrient deficiencies. While these symptoms can have many causes, they're worth paying attention to when they appear unexpectedly or persist without an obvious explanation.
Different symptoms can offer different clues. Bleeding gums may be associated with inadequate vitamin C, while dry skin and dandruff can sometimes occur with low vitamin B2. Hair loss has been linked with deficiencies in iron, vitamin C, zinc and vitamin D, while brittle nails may be associated with inadequate biotin or, more commonly, zinc. Persistent fatigue can also occur when you're low in vitamin D, iron or several B vitamins.
Rather than automatically reaching for a supplement when one of these symptoms appears, start by looking at the quality and variety of the foods you're eating. Restrictive diets and simply not eating enough can make it harder to meet your nutritional needs. If symptoms persist, testing can help identify whether you're actually deficient before deciding what you need. Whenever possible, prioritize getting nutrients from a varied, whole-food diet and address specific deficiencies based on your individual needs.
SOURCE:
UCLA Health, September 8, 2026