# item.guide
Side-by-Side Comparison Essential Vitamins & Minerals

Vitamin A (Retinol & Beta-Carotene) vs. Vitamin C (L-Ascorbic Acid)

Comparing 2 standards across 9 specifications. 9 key differences identified.

Comparing:
Vitamin A (Retinol & Beta-Carotene)
Vitamin C (L-Ascorbic Acid)
Vitamin A (Retinol & Beta-Carotene) →

Vitamin A is an essential fat-soluble isoprenoid comprising preformed retinol and provitamin A carotenoids. Adult RDA is 900 µg RAE (men) / 700 µg RAE (women), with a Tolerable Upper Limit of 3,000 µg/day preformed retinol, essential for rhodopsin retinal photoreception, epithelial differentiation, and immune cell proliferation.

View full Vitamin A (Retinol & Beta-Carotene) spec sheet →
Vitamin C (L-Ascorbic Acid) →

Vitamin C is a water-soluble electron donor and antioxidant essential for collagen proline/lysine hydroxylation, non-heme iron absorption, and immune phagocyte function. Adult RDA is 90mg (men) / 75mg (women), with a Tolerable Upper Limit of 2,000mg/day.

View full Vitamin C (L-Ascorbic Acid) spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Vitamin A (Retinol & Beta-Carotene)
Vitamin C (L-Ascorbic Acid)
Nutrient Type
Fat-Soluble Isoprenoid Vitamin Water-Soluble Vitamin
Adult RDA / RDI
900 µg RAE / day (Men) / 700 µg RAE / day (Women) 90 mg (Men) / 75 mg (Women) (+35mg for smokers)
Tolerable Upper Limit (UL)
3,000 µg / day (10,000 IU) (Preformed retinol only; no UL for beta-carotene) 2,000 mg / day (Avoid osmotic diarrhea)
Chemical Forms
Retinyl Palmitate (Preformed Animal), All-Trans Retinol, Beta-Carotene (Plant Provitamin) L-Ascorbic Acid, Sodium Ascorbate, Calcium Ascorbate
Primary Biological Function
11-cis-retinal rhodopsin visual cycle, RAR/RXR nuclear receptor gene transcription, Mucosal barrier immunity Prolyl/Lysyl Hydroxylase cofactor (Collagen), ROS scavenger, Carnitine synthesis
Deficiency Condition
Nyctalopia (Night blindness), Xerophthalmia, Bitot's spots, Keratinization of mucous membranes Scurvy (Collagen breakdown, capillary fragility, impaired wound healing)
Top Whole Food Sources
Beef Liver, Cod Liver Oil, Sweet Potatoes, Carrots, Spinach, Curly Kale, Butter Red Bell Pepper, Strawberries, Citrus, Kiwi, Broccoli, Brussels Sprouts
Hepatic Storage
80–90% of total body Vitamin A is stored in hepatic stellate cells as retinyl esters —
Thermolability
— Highly heat- and oxygen-sensitive (degrades rapidly with prolonged boiling)

Other Alternatives to Compare

Compare Vitamin A (Retinol & Beta-Carotene) vs. Calcium (Elemental Ca) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Iodine (Elemental I) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Iron (Heme & Non-Heme) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Magnesium (Elemental Mg) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Potassium (Elemental K) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Selenium (Elemental Se) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Sodium (Elemental Na) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin B1 (Thiamine) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin B12 (Cobalamin) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin B2 (Riboflavin) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin B3 (Niacin / Nicotinic Acid & Nicotinamide) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin B5 (Pantothenic Acid) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin B6 (Pyridoxal 5'-Phosphate / PLP) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin B7 (Biotin / Vitamin H) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin B9 (Folate & Folic Acid) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin D3 (Cholecalciferol) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin E (d-Alpha-Tocopherol) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Vitamin K1 (Phylloquinone) → Compare Vitamin A (Retinol & Beta-Carotene) vs. Zinc (Elemental Zn) →