Signs and Symptoms of Vitamin D Deficiency in Adults

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iSigns and Symptoms of Vitamin D Deficiency in Adults

Vitamin D deficiency in adults often causes few short-term signs and symptoms. A longstanding deficiency may cause bone- and muscle-related signs and symptoms.

Your body manufactures vitamin D when exposed to sunlight. Dietary sources include foods that naturally contain or are fortified with vitamin D, and nutritional supplements. Vitamin D is essential for a healthy bones and muscles, supports immune system function, regulates cell growth and participates in a variety of cellular functions. Vitamin D deficiency in adults is often clinically silent, meaning it frequently causes no symptoms. A longstanding deficiency, however, might lead to symptoms primarily involving the bones and muscles. Similarly, observable signs of a vitamin D deficiency in adults usually involve the skeletal system.

Musculoskeletal Symptoms

From a medical perspective, a symptom is something an individual experiences in association with a disease or condition. Among adults who develop symptoms related to a vitamin D deficiency, these symptoms almost exclusively affect the musculoskeletal system -- the bones and muscles. These symptoms may include:

  • Gradually developing bone pain and tenderness, especially of the low back and hips
  • Weakness of the proximal muscles, meaning those of thighs, pelvis and shoulders
  • Spasms of the muscles of the hands and/or feet
  • Difficulty walking or a waddling walking pattern 
  • Lack of energy and fatigue

These symptoms arise primarily because a vitamin D deficiency disrupts normal calcium and phosphorus metabolism, which weakens the bones and interferes with normal muscle function.

Bone Signs

Medically speaking, a sign is an observable consequence of a disease or condition. Signs associated with a vitamin D deficiency in adults develop when the condition is longstanding. Signs associated with vitamin D deficiency involve the bones, which become weak due to poor incorporation of calcium and phosphorus. Signs of a vitamin D deficiency in adults include:

  • Decreased bone mineral density seen with dual-energy x-ray absorptiometry (DEXA) testing
  • Areas of demineralized bone (Looser zones) on routine x-rays, most often involving the thigh and shin bones, pelvis, shoulder and ribs
  • Nontraumatic bone fractures, especially of the spine, hip and ribs
  • Spinal curvature leading to a forward leaning posture
  • Reduced muscle reflexes
  • Low blood levels of vitamin D

Causes and Risk Factors

Several factors can lead to a vitamin D deficiency in adults. Inadequate dietary intake and lack of sun exposure are primary causes, but other factors can contribute to or increase your risk for this nutritional deficiency, including:

  • People with black or brown skin (due to decreased vitamin D production with sun exposure)
  • Chronic kidney disease
  • Obesity or prior gastric bypass surgery
  • Chronic liver disease, Crohn disease, pancreatic disease and cystic fibrosis
  • Advanced age (seniors)
  • Reduced parathyroid gland function

Other Considerations

The potential role of a reduced vitamin D level in a variety of diseases and conditions is an active area of research interest. Diseases and conditions that might be influenced by vitamin D levels include diabetes, heart disease, high blood pressure, cancer, autoimmune diseases and mental health disorders. Ongoing and future research may lead to further clarification of the potential preventative or treatment-related role of vitamin D for one or more of these conditions.

If you are concerned that you might have a vitamin D deficiency, talk with your doctor -- especially if you have risk factors for this vitamin deficiency.

Reviewed and revised by: Tina M. St. John, M.D.