Which nutritional deficiency is most commonly associated with xerosis (dry, rough skin)?

Nutritional Deficiencies Associated with Xerosis

Vitamin A deficiency is the most clinically significant nutritional deficiency causing xerosis, presenting with characteristic dry, rough skin alongside pathognomonic ocular findings like Bitot spots and night blindness. 1

Primary Nutritional Deficiency: Vitamin A

• Vitamin A deficiency causes xerophthalmia (dry eyes) and xerosis cutis (dry skin) as cardinal manifestations, progressing from night blindness to conjunctival xerosis, Bitot spots, and ultimately keratomalacia if untreated 1
• The skin manifestations include generalized dry, rough, scaly skin that reflects impaired epithelial cell differentiation and keratinization 1
• Immediate treatment requires high-dose oral vitamin A: 200,000 IU on day 1, day 2, and again at 1-4 weeks for adults and children ≥12 months 1
• High-risk populations include patients with chronic liver disease, chronic alcohol use, malabsorption syndromes, post-bariatric surgery patients, and those with chronic kidney disease 1

Secondary Nutritional Deficiencies

Essential Fatty Acids

• Essential fatty acid (EFA) deficiency produces severe cutaneous abnormalities including xerosis, though this is exceedingly rare in clinical practice 2
• When fat-free medical foods are provided or diets contain inadequate linoleic and α-linolenic acid, EFA status should be monitored and supplementation may be necessary 3
• Deficiency manifests as dry, scaly, rough skin with impaired barrier function 2

Vitamin D

• While vitamin D deficiency primarily affects bone health (rickets, osteoporosis), it may contribute to impaired skin barrier function 3
• However, the direct causal relationship between vitamin D deficiency and xerosis is not well-established in clinical guidelines 3

B Vitamins

• Vitamin B12 and B6 deficiency can occur with inadequate consumption of animal protein or medical foods, though skin manifestations are not the primary presenting feature 3
• Niacin (vitamin B3) excess rather than deficiency causes skin irritation and rashes 3

Clinical Context: Xerosis in Specific Populations

Dialysis Patients

• Xerosis is the most common cutaneous sign in patients on dialysis, though it does not necessarily correlate with pruritus 3
• The mechanism is multifactorial and not purely nutritional—use of emollients is essential regardless of nutritional status 3

Drug-Induced Xerosis

• Interferon causes xerosis in 10% of cases, while ribavirin causes it in 30% of cases during hepatitis C treatment 3
• This is a pharmacologic effect rather than a nutritional deficiency 3

Diagnostic Approach

• For suspected vitamin A deficiency: measure serum retinol levels (normal >0.70 μmol/L or >20 μg/dL), but do not delay treatment waiting for results if clinical signs are present 1
• Critical caveat: serum retinol decreases with inflammation, so adjust interpretation for inflammatory markers (CRP, AGP) 1
• Screen for concurrent micronutrient deficiencies including iron, folate, and vitamin C in malnourished patients 1

Treatment Priorities

• Never delay vitamin A treatment waiting for laboratory confirmation when Bitot spots or other pathognomonic signs are present—this is a clinical diagnosis requiring immediate intervention 1
• After acute vitamin A repletion, continue preventive supplementation: 200,000 IU every 3 months for children 12 months to 5 years 1
• For xerosis without clear vitamin A deficiency, basic emollient therapy with urea-containing formulations is the mainstay of treatment 4, 5