What are the possible causes and step-wise treatment options for vertigo in healthy adults with normal blood pressure, but deficient in vitamin D and hemoglobin?

Causes and Treatment of Vertigo in Healthy Adults with Vitamin D and Hemoglobin Deficiency

Possible Causes of Vertigo

Benign Paroxysmal Positional Vertigo (BPPV) is the most common cause of vertigo in otherwise healthy adults, accounting for 42% of all vertigo cases, and vitamin D deficiency is strongly associated with both its occurrence and recurrence. 1

Primary Vestibular Causes

• BPPV presents with brief episodes of vertigo (lasting seconds to <1 minute) triggered by specific head position changes, and is diagnosed by the Dix-Hallpike maneuver showing characteristic torsional upbeating nystagmus with 5-20 second latency 1, 2
• Vestibular migraine accounts for 14% of all vertigo cases and is extremely under-recognized, presenting with episodes lasting minutes to hours accompanied by headache, photophobia, or phonophobia 1
• Ménière's disease presents with episodic vertigo lasting hours, accompanied by fluctuating hearing loss, tinnitus, and aural fullness 3, 1
• Vestibular neuritis causes acute persistent vertigo lasting days to weeks with continuous symptoms 1

Metabolic and Nutritional Factors

• Vitamin D deficiency is directly linked to BPPV occurrence and recurrence, with patients having significantly lower serum 25(OH)D levels (12-15 ng/mL) compared to controls 4, 5, 6, 7
• Anemia from low hemoglobin can cause lightheadedness and presyncope rather than true vertigo, though this represents cardiovascular rather than vestibular pathology 1
• Pantothenic acid deficiency (though rare) can cause postural hypotension and vertigo, as experimentally demonstrated 3

Medication-Related Causes

• Antihypertensives, sedatives, anticonvulsants, and psychotropic drugs are leading reversible causes of chronic dizziness 1

Step-Wise Treatment Algorithm

Step 1: Immediate Diagnostic Evaluation

Perform the Dix-Hallpike maneuver bilaterally as the first diagnostic test to identify or exclude BPPV. 1, 2

• Look for characteristic findings: torsional and upbeating nystagmus with 5-20 second latency, crescendo-decrescendo pattern that resolves within 60 seconds, and fatigability with repeat testing 1, 2
• If positive with typical findings, proceed immediately to treatment without imaging 1
• If negative or atypical findings (immediate onset, persistent nystagmus, purely vertical without torsional component), consider central causes requiring urgent MRI 1, 2

Step 2: First-Line Treatment for Confirmed BPPV

Perform canalith repositioning procedures (Epley maneuver) immediately upon diagnosis, which has 80% success after 1-3 treatments and 90-98% success with repeat maneuvers. 1, 2, 8

• Do NOT prescribe vestibular suppressant medications routinely for BPPV, as they prevent central compensation 2
• Do NOT order imaging or vestibular testing for typical BPPV with positive Dix-Hallpike and no red flags 1, 2
• Reassess within 1 month to document resolution or persistence 1

Step 3: Address Vitamin D Deficiency

Measure serum 25(OH)D levels and supplement if deficient (<30 ng/mL), as vitamin D supplementation significantly reduces BPPV recurrence (RR = 0.37; 95% CI = 0.18-0.76). 4, 5, 6, 7

• For vitamin D insufficiency (serum 25(OH)D <30 ng/mL), administer vitamin D2 50,000 units orally every month for 6 months 3
• Vitamin D supplementation is particularly important for patients with recurrent BPPV, as those with chronic recurrent episodes have significantly lower vitamin D levels (12.6 ng/mL) than those without recurrence (18.3 ng/mL) 7
• Continue supplementation to maintain serum 25(OH)D >30 ng/mL for secondary prevention 4, 5

Step 4: Evaluate and Treat Anemia

Check complete blood count and iron studies to identify the cause of low hemoglobin, as anemia typically causes lightheadedness rather than true vertigo. 3

• For hemoglobin <12 g/dL in women or <13 g/dL in men with GFR <30 mL/min per 1.73 m², perform complete anemia workup including iron studies 3
• Treat identified iron deficiency appropriately 3
• If anemia persists despite iron therapy, consider erythropoietin or analogue 3
• Note: Anemia-related dizziness presents as lightheadedness or presyncope, not rotational vertigo, and should be distinguished from vestibular causes 1

Step 5: Treatment Failures and Persistent Symptoms

If symptoms persist after initial Epley maneuver, repeat the Dix-Hallpike test and perform additional canalith repositioning maneuvers. 1, 2

• Success rate increases to 90-98% with repeated procedures 1, 2
• If BPPV persists despite multiple repositioning attempts, refer for vestibular rehabilitation therapy 1
• Vestibular rehabilitation significantly improves gait stability compared to medication alone and is particularly beneficial for elderly patients or those with heightened fall risk 1

Step 6: Consider Alternative Diagnoses

If Dix-Hallpike is negative or symptoms are atypical, evaluate for vestibular migraine, Ménière's disease, or central causes. 1

• For vestibular migraine: Assess for current/past migraine history, family history, and whether photophobia, phonophobia, or visual aura occur during vertigo episodes; treat with migraine prophylaxis and lifestyle modifications 1
• For Ménière's disease: Look for fluctuating hearing loss, tinnitus, and aural fullness; obtain audiogram; treat with low-sodium diet (1500-2300 mg daily), diuretics, and vestibular rehabilitation 3, 1
• For medication-induced dizziness: Review and adjust antihypertensives, sedatives, anticonvulsants, and psychotropic drugs 1

Red Flags Requiring Urgent Neuroimaging

Order MRI brain without contrast immediately if any of the following are present: 1, 9, 2

• Focal neurological deficits on examination
• Sudden unilateral hearing loss
• Inability to stand or walk
• Downbeating nystagmus or other central nystagmus patterns (purely vertical without torsional component, direction-changing without head position changes)
• New severe headache accompanying dizziness
• Failure to respond to appropriate peripheral vertigo treatments
• Positive Romberg test with vertigo (suggests central pathology)

Common Pitfalls to Avoid

• Do NOT rely on patient descriptions of "spinning" versus "lightheadedness"—focus on timing, triggers, and duration instead 1
• Do NOT assume normal neurologic exam excludes stroke, as 75-80% of patients with posterior circulation infarct causing acute vestibular syndrome have no focal neurologic deficits 1
• Do NOT order CT head for isolated vertigo, as it has <1% diagnostic yield and misses most posterior circulation infarcts; MRI with diffusion-weighted imaging is far superior (4% vs <1% yield) 1
• Do NOT prescribe meclizine or other vestibular suppressants for BPPV, as they delay central compensation 2, 8
• Do NOT overlook vitamin D deficiency as a modifiable risk factor for BPPV recurrence 4, 5, 6, 7