Symptoms of Vitamin D Deficiency
Vitamin D deficiency commonly manifests as symmetric low back pain, proximal muscle weakness, muscle aches, throbbing bone pain (especially when pressure is applied over the sternum or tibia), fatigue, and unexplained anemia. 1, 2
Clinical Presentation
Vitamin D deficiency can present with various symptoms that affect multiple body systems:
Musculoskeletal Symptoms
- Bone pain (often aching in nature)
- Symmetric low back pain
- Proximal muscle weakness (difficulty standing from a squatting position)
- Muscle aches and pains (often misdiagnosed as fibromyalgia or chronic pain syndrome)
- Increased risk of falls due to muscle weakness 1, 2
Other Common Symptoms
- Fatigue and general tiredness
- Unexplained anemia
- Depression or mood changes
- Impaired cognitive function 1, 3
Severe Deficiency Consequences
If left untreated, vitamin D deficiency can lead to more serious conditions:
- In children: Rickets (poor mineralization of bones leading to growth retardation and bone deformities)
- In adults: Osteomalacia (poor mineralization of newly formed bone matrix causing pain)
- Secondary hyperparathyroidism
- Increased risk of osteoporosis and fractures
- Increased mortality risk 1, 4
High-Risk Populations
Certain groups are particularly susceptible to vitamin D deficiency:
- Elderly individuals, especially those institutionalized
- People with darker skin pigmentation (70.6% of African Americans and 44.2% of Hispanics have deficient levels)
- Individuals with limited sun exposure due to geographic location or cultural practices
- Patients with chronic kidney or liver disease
- Obese individuals
- Infants who are exclusively breastfed without supplementation
- Individuals with malabsorption conditions 1
Clinical Pearls and Pitfalls
- Important pitfall: Vitamin D deficiency is often misdiagnosed as fibromyalgia, chronic pain syndrome, or simply dismissed as depression 5
- Muscle symptoms may be the first manifestation of vitamin D deficiency, even before bone abnormalities become apparent
- Treatment response can be excellent, with 85.54% of patients regaining the ability to stand from a squatting position after 2-6 months of treatment 1
- Vitamin D deficiency is pandemic but often unrecognized, making awareness of its symptoms crucial for timely diagnosis 5
Diagnostic Approach
- Serum 25-hydroxyvitamin D (25-OHD) is the gold standard test for diagnosing vitamin D deficiency
- Deficiency is defined as levels < 20 ng/mL (50 nmol/L)
- Insufficiency is defined as levels between 21-29 ng/mL (50-75 nmol/L) 1, 2
Remember that symptoms of vitamin D deficiency can be subtle and nonspecific, making it important to consider testing in high-risk individuals even when classic symptoms are not prominent.