Can vitamin D deficiency cause muscle pain?

Vitamin D Deficiency and Muscle Pain

Yes, vitamin D deficiency can cause muscle pain and is a common but often overlooked cause of musculoskeletal symptoms including muscle weakness, aches, and pain. 1, 2

Clinical Manifestations of Vitamin D Deficiency

Vitamin D deficiency commonly presents with several musculoskeletal symptoms:

• Muscle pain: Often symmetric, diffuse, and may be elicited with pressure over bones 2
• Proximal muscle weakness: Difficulty standing from a seated position or climbing stairs 3
• Muscle fatigue: General tiredness and reduced exercise tolerance 4
• Bone pain: Particularly in the lower back, sternum, or tibia 2
• Gait disturbances: Including waddling gait due to proximal myopathy 5

Prevalence and Risk Factors

Vitamin D deficiency is extremely common:

• 25-50% of patients in clinical practice are deficient 3
• Higher prevalence in:
  • Individuals with darker skin pigmentation (70.6% of African Americans) 1
  • Elderly and institutionalized persons 4
  • Those with limited sun exposure due to cultural practices (e.g., religious garments) 5
  • Individuals with malabsorption conditions 1
  • Those living in northern latitudes 1

Diagnosis

When muscle pain is present, vitamin D deficiency should be considered:

• Measurement of 25-hydroxyvitamin D (25-OHD) is the gold standard test 2
• Deficiency definition: Serum 25-OHD level <20 ng/mL (50 nmol/L) 2
• Insufficiency definition: Serum 25-OHD level 20-30 ng/mL (50-75 nmol/L) 2

Additional testing to consider:

• Calcium and phosphorus levels (may be low) 5
• Parathyroid hormone (often elevated due to secondary hyperparathyroidism) 4
• Alkaline phosphatase (may be elevated) 4

Treatment Approach

For patients with vitamin D deficiency and muscle pain:

1. High-dose vitamin D supplementation:

   • Oral ergocalciferol (vitamin D2) 50,000 IU weekly for 8-12 weeks 1, 2
   • Alternatively, cholecalciferol (vitamin D3) at equivalent doses

2. Maintenance therapy after normalization:

   • Cholecalciferol (vitamin D3) 800-1,000 IU daily 2
   • Higher doses (1,500-4,000 IU daily) for high-risk individuals 1

3. Calcium supplementation:

   • Ensure adequate calcium intake (1,000-1,200 mg daily) 1

4. Monitoring:

   • Measure 25(OH)D levels after 3-6 months of therapy 1
   • Watch for improvement in symptoms (typically within 2-6 months) 3

Expected Outcomes

Treatment response is typically excellent:

• In a study of patients with vitamin D deficiency and proximal myopathy, 85.54% regained the ability to stand from a squatting position after 2-6 months of treatment 3
• Muscle pain and weakness often improve significantly with supplementation 5, 6
• The more severe the deficiency (<10 ng/dL), the more dramatic the improvement with treatment 3

Important Considerations

• Vitamin D deficiency is often overlooked as a cause of muscle pain and weakness 6
• Symptoms may be misdiagnosed as fibromyalgia, chronic fatigue syndrome, or age-related weakness 4
• Severe deficiency can lead to secondary hyperparathyroidism and osteomalacia if left untreated 5
• Vitamin D supplementation has been shown to reduce fall risk by 19% with doses of 700-1,000 IU/day 7

For patients presenting with unexplained muscle pain, especially if accompanied by proximal weakness, fatigue, or bone pain, vitamin D levels should be checked, as this represents a treatable cause of these symptoms with excellent outcomes when properly addressed.