Signs of nutritional deficiency can manifest in various ways, including unexplained fatigue, hair loss, brittle nails, and muscle weakness. Other indicators may include frequent illnesses or infections, poor wound healing, and cognitive difficulties. Specific symptoms often correlate with particular nutrients; for example, iron deficiency may lead to anemia, while vitamin D deficiency can result in bone pain. Monitoring dietary intake and seeking medical advice when these signs occur is crucial for identifying and addressing potential deficiencies effectively.