What are the symptoms of vitamin D deficiency?

Symptoms of Vitamin D Deficiency

Vitamin D deficiency commonly presents with bone pain, muscle weakness, fatigue, and increased risk of fractures, and should be suspected in patients with these symptoms, especially those with risk factors for deficiency. 1

Clinical Manifestations

Common Symptoms

• Musculoskeletal symptoms:
  • Symmetric low back pain 2
  • Proximal muscle weakness 2
  • Muscle aches and myalgia 3, 2
  • Throbbing bone pain (especially when pressure is applied over the sternum or tibia) 2
  • Difficulty standing from a squatting position 1

Advanced Deficiency Symptoms

• Osteomalacia in adults (painful bone disease) 1, 4
• Increased risk of falls due to muscle weakness 1, 5
• Increased fracture risk 1, 4
• Unexplained anemia 1
• Secondary hyperparathyroidism 1

Risk Factors for Vitamin D Deficiency

Identifying patients at risk is crucial for early diagnosis:

• Limited UVB exposure/insufficient sun exposure 1
• Inadequate dietary vitamin D intake 1
• Darker skin pigmentation (70.6% of African Americans have deficient levels) 1
• Advanced age (especially institutionalized elderly) 1, 3
• Obesity 1
• Malabsorption conditions 1
• Severe liver or kidney disease 1
• Cultural practices limiting sun exposure 1
• Geographic location (northern latitudes) 1
• Prolonged breastfeeding without supplementation 6

Diagnostic Considerations

Vitamin D deficiency is defined as serum 25-hydroxyvitamin D (25-OHD) levels:

• Deficiency: <20 ng/mL (<50 nmol/L) 1, 2
• Insufficiency: 20-30 ng/mL (50-75 nmol/L) 1, 2
• Severe deficiency: <12 ng/mL (<30 nmol/L) 1

Clinical Pitfalls and Important Considerations

• Vitamin D deficiency is often misdiagnosed as fibromyalgia or chronic pain syndrome 4
• Symptoms may be dismissed as depression 4
• Osteoporosis (caused by vitamin D deficiency) is painless, while osteomalacia causes aching bone pain 4
• Vitamin D deficiency is pandemic but frequently overlooked 4, 2
• Symptoms may be subtle in early deficiency but can progress to significant disability 2
• Polypharmacy in elderly patients can interfere with vitamin D metabolism through cytochrome CYP3A4 interactions 3
• Vitamin D toxicity is rare but possible at very high levels >500 nmol/L (>200 ng/mL) 1

Special Populations

Children

• Rickets (bone mineralization disease) 1
• Growth problems 7

Elderly

• Higher prevalence of deficiency 1, 3
• Increased risk of sarcopenia (loss of muscle mass and strength) 3
• Greater risk of frailty syndrome 3
• Higher fall and fracture risk 1, 3

Postmenopausal Women

• Increased bone turnover 7
• Decreased bone mineral density 7
• Elevated fracture risk 7

Early recognition of these symptoms, particularly in high-risk populations, can lead to appropriate testing and treatment, significantly improving quality of life and preventing serious complications such as fractures and falls.