• Bone-related issues: Reduced bone strength, increasing the risk of fractures, particularly due to conditions like osteomalacia (softening of the bones in adults) and rickets (bone weakness and abnormal development in children).
• Pain and muscle weakness: Bone pain, muscle weakness, numbness, and difficulty walking, especially in severe and prolonged cases.
• Other health risks: Some research suggests that vitamin D deficiency may be linked to higher rates of cancer, autoimmune diseases, cardiovascular disorders, metabolic issues, and even higher mortality rates. However, a direct causal link has yet to be proven.
• Osteoporosis: Low bone density and bone loss, which can lead to fractures and osteoporosis, particularly in older adults.
• Hair loss: A possible side effect linked to vitamin D deficiency.
• Fatigue: General tiredness and fatigue are often reported symptoms.
• Calcium and phosphate imbalance: Vitamin D deficiency can lead to hypocalcemia (low calcium levels) and hypophosphatemia (low phosphate levels).
• Hyperparathyroidism: Secondary hyperparathyroidism may occur, which can cause further bone demineralization.

Most people with a vitamin D deficiency don’t show any symptoms, but complications can still arise. These vary depending on the severity and duration of the deficiency. Some of the most common complications include:

While many people with vitamin D deficiency experience no symptoms, addressing it early can prevent long-term complications.