Deficiency/Immunity/Beauty

Vitamin A

Fat-soluble vitamin essential for vision and immune function, most useful for adults with low intake or malabsorption.

Vitamin A

Fat-soluble vitamin essential for vision and immune function, most useful for adults with low intake or malabsorption.

score

evidence

Caution

risk

Overview

Forms

Safety

Stack

Quick Take

Worth it if intake is low or malabsorption risk is real — otherwise skip extra retinol, especially high-dose products.

Vitamin A is a fat-soluble nutrient found as retinol in liver, eggs, dairy, and cod liver oil and as provitamin A carotenoids in carrots, sweet potatoes, and leafy greens. Retinal is needed for low-light vision, while retinoic acid regulates genes involved in epithelial and immune function. Supplementation is most useful for correcting deficiency, reversing night blindness, supporting skin barriers, and improving immune resilience in people with low status or fat-malabsorption.

Proven Benefits

Corrects vitamin A deficiency

Restores night vision in deficiency

Reduces measles complications

Supports immune defense if low

Supports skin barrier if low

Improves hemoglobin if low

May lower respiratory infections

May improve acne

Protocol

Amount

2500-3000 IU

Frequency

Once daily

When

With a meal containing fat to improve absorption.

Onset Time

2-6 weeks for symptoms; 1-3 months for lab changes

Who Should Consider

Adults with confirmed low serum retinol

People with fat malabsorption

Bariatric surgery patients

Very restrictive eaters with low vitamin A intake

Food Sources

Beef liver (~6500 mcg RAE per 85 g)
Sweet potato, baked (~1100 mcg RAE each medium)
Carrots, cooked (~500-650 mcg RAE per 1/2 cup)
Spinach, cooked (~500-600 mcg RAE per 1/2 cup)
Egg yolks (~75-100 mcg RAE each)
Whole milk or fortified dairy (~70-150 mcg RAE per cup)

How It Works

Vitamin A acts through retinal and retinoic acid. Retinal is required for rhodopsin, the light-sensing pigment in the retina, while retinoic acid binds nuclear receptors that regulate gene expression involved in epithelial integrity, immune-cell differentiation, and normal growth.

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