When vitamin D levels are low, it can lead to various health issues. Vitamin D is essential for calcium absorption, bone health, immune function, and modulation of gene expression. Low vitamin D levels may contribute to conditions such as osteoporosis, increased risk of fractures, muscle weakness, compromised immune system, fatigue, depression, hair loss, impaired wound healing, and other health complications. It's important to address vitamin D deficiency through appropriate interventions, such as sunlight exposure, dietary adjustments, and supplementation under the guidance of a healthcare provider, to maintain optimal vitamin D levels and promote overall health.