What are the symptoms of vitamin D deficiency?

Symptoms of Vitamin D Deficiency

Vitamin D deficiency presents with various symptoms affecting multiple body systems, primarily manifesting as musculoskeletal complaints, fatigue, and in severe cases, bone mineralization disorders.

Common Clinical Manifestations

• Musculoskeletal symptoms are the most frequent presentation:

  • Symmetric low back pain 1
  • Proximal muscle weakness 1, 2
  • Muscle aches and myopathy 1, 2
  • Throbbing bone pain (especially when pressure is applied over the sternum or tibia) 1
  • Gait disturbances 2

• General symptoms that may be overlooked:

  • Fatigue and weakness 3, 1
  • General aches and pains 4
  • Increased risk of falls (especially in older adults) 5

• Advanced deficiency can lead to:

  • Osteomalacia in adults (painful bone disease with reduced mineralization) 1, 2
  • Rickets in children (visible skeletal changes) 6, 4
  • Deep bone pain 2
  • Low-energy fractures 2

Laboratory Findings

• Vitamin D deficiency is defined as serum 25-hydroxyvitamin D levels:

  • Deficiency: <20 ng/mL (50 nmol/L) 1, 6
  • Insufficiency: 20-30 ng/mL (50-75 nmol/L) 1
  • Optimal levels: 30-60 ng/mL 5

• Associated laboratory abnormalities may include:

  • Elevated alkaline phosphatase 2
  • Elevated parathyroid hormone (secondary hyperparathyroidism) 2
  • Low calcium and phosphorus levels (in severe cases) 6

Special Populations at Higher Risk

• Bariatric surgery patients may experience:

  • Unexplained anemia 6
  • Fatigue 6
  • Increased risk of fractures 6

• Patients with inflammatory bowel disease may present with:

  • Bone pain 6
  • Increased fracture risk 6
  • Secondary hyperparathyroidism 6

• Elderly patients commonly experience:

  • Increased fall risk 5
  • Muscle weakness 2
  • Higher fracture rates 2

Non-Skeletal Manifestations

• Emerging evidence links vitamin D deficiency to:
  • Depression and impaired cognitive function 4
  • Increased risk of cardiovascular disease 4
  • Metabolic syndrome and type 2 diabetes 4
  • Increased overall mortality 4
  • Potential increased cancer risk 2

Clinical Pitfalls

• Symptoms may be subtle and nonspecific, leading to delayed diagnosis 1
• Screening based only on alkaline phosphatase or PTH will miss many cases 2
• Vitamin D deficiency is often overlooked in patients with unexplained musculoskeletal pain 1
• Individual variation exists in vitamin D metabolism based on genotype, phenotype, and environmental conditions 3

Diagnostic Approach

• Obtain 25-hydroxyvitamin D level in patients with suspected deficiency 1
• Consider vitamin D testing in patients with unexplained:
  • Musculoskeletal pain 1
  • Proximal muscle weakness 1, 2
  • Bone pain 1
  • Frequent falls (especially in elderly) 5
  • Unexplained anemia 6

Remember that vitamin D deficiency is pandemic in adults and can significantly impact quality of life and increase fracture risk if left untreated 5.