What is Vitamin A?

Vitamin A is a fat-soluble vitamin essential for many bodily functions, including vision, immune health, and cellular communication. It exists in two primary forms:

Preformed Vitamin A (Retinol and Retinyl Esters): Found in animal products such as liver, fish, and dairy.
Provitamin A Carotenoids: Plant-based compounds (like beta-carotene) that the body converts into active Vitamin A.

What Types of Vitamin A Are There and What Do They Do?

Retinol: Supports immune function, skin health, and reproduction.
Retinyl Esters: A storage form of Vitamin A found in animal products.
Beta-Carotene: An antioxidant that protects cells and can be converted to retinol in the body.
Other Carotenoids (e.g., alpha-carotene, lutein): Play roles in eye health and as antioxidants but are less efficient in conversion to Vitamin A.

Daily Requirements for Vitamin A

Recommended Dietary Allowances (RDAs):

Infants (0-12 months): 300-400 mcg RAE (Retinol Activity Equivalents)
Children (1-8 years): 300-400 mcg RAE
Adolescents (9-18 years): 600-900 mcg RAE
Adult Men: 900 mcg RAE
Adult Women: 700 mcg RAE
Pregnant Women: 770 mcg RAE
Lactating Women: 1,300 mcg RAE

What Does Vitamin A Do in Our Body?

Vision: Essential for the production of rhodopsin, a pigment critical for low-light and color vision.
Immune Function: Strengthens mucosal barriers and enhances the activity of white blood cells.
Cellular Growth and Differentiation: Supports skin and tissue repair.
Reproduction: Vital for fetal development and reproductive health.
Antioxidant Properties: Carotenoids neutralize free radicals, reducing oxidative stress.

Symptoms of Vitamin A Deficiency

Early Signs: Night blindness, dry eyes, and skin issues.
Progressive Signs: Impaired immune function, increased infection risk, and keratinization of epithelial tissues.
Severe Deficiency: Blindness and growth retardation in children.

What Does Vitamin A Do for Our Thyroid Pathway?

Thyroid Hormone Synthesis: Facilitates the production and regulation of thyroid hormones.
Conversion Support: Enhances the conversion of T4 (inactive) to T3 (active thyroid hormone).
Immune-Modulating Effects: Reduces thyroid autoimmunity risks by modulating immune response.

What Does Vitamin A Do for Our Liver?

Storage: The liver stores about 90% of the body’s Vitamin A reserves.
Detoxification Support: Antioxidant properties protect the liver from oxidative damage.
Fat Metabolism: Helps regulate lipid levels, reducing fatty liver risk.

What Does Vitamin A Do for Our Gut?

Mucosal Barrier Integrity: Maintains gut lining, preventing leaky gut.
Immune Regulation: Supports gut-associated lymphoid tissue (GALT).
Microbiome Balance: Promotes the growth of beneficial gut bacteria.

Physical Ailments That Affect Vitamin A

Liver Disease: Reduces storage capacity.
Celiac Disease: Impairs absorption due to intestinal damage.
Pancreatic Insufficiency: Limits fat digestion, reducing Vitamin A uptake.
Kidney Disease: Affects metabolism and excretion.

Food That Impacts Vitamin A

Enhancers: Fats improve absorption of Vitamin A.
Inhibitors: Alcohol and processed foods can impair absorption and storage.

Medications That Impact Vitamin A

Negatively: Orlistat, cholestyramine, and retinoid-based acne medications.
Positively: Certain zinc supplements improve Vitamin A metabolism.

Natural Supplements That Negatively Impact Vitamin A

High-Dose Vitamin E: Competes for absorption.
Iron Deficiency Supplements: Can alter Vitamin A metabolism if unbalanced.

Heavy Metals That Impact Vitamin A

Lead and Cadmium: Disrupt Vitamin A metabolism in the liver and kidneys.
Mercury: Damages organs responsible for Vitamin A storage and use.

Testing for Vitamin A

Serum Retinol Levels: Reflect short-term Vitamin A status.
Liver Biopsy: Measures long-term storage but is invasive.
Retinol-Binding Protein (RBP): Indicates transport efficiency.

Nutrients Required for Vitamin A Absorption

Zinc: Vital for converting and transporting Vitamin A.
Fat: Enhances absorption since Vitamin A is fat-soluble.
Protein: Necessary for retinol-binding protein synthesis.

Foods High in Vitamin A

Animal Sources: Liver (beef, chicken), fish oils, eggs, and dairy products.
Plant Sources: Carrots, sweet potatoes, spinach, and mangoes (rich in beta-carotene).

A Recipe High in Vitamin A

**Carrot and Sweet Potato Soup**

Ingredients: 2 lge sweet potatoes peeled and diced, 3 carrots chopped, 1 onion diced, 3 cups chicken stock, 1 cup coconut milk, 1 tsp turmeric, salt & Pepper to taste
Instructions: Heat olive oil in a pot and saute onions until soft, add sweet potatoes, carrots, turmeric and stock. Simmer until tender then blend until smooth with coconut milk. Season.

Other Random Information About Vitamin A

Toxicity Risk: Excess intake, particularly from animal sources, can lead to hypervitaminosis A, causing nausea, liver damage, and bone pain.
Seasonal Variations: Beta-carotene levels in vegetables can vary with growing conditions.
Genetic Variations: Some individuals have reduced ability to convert beta-carotene to active Vitamin A due to genetic factors.

Disclaimer: The information provided in this article is for educational purposes only and is not intended to diagnose, treat, or cure any medical condition. Always consult with a qualified healthcare professional before making any changes to your diet, lifestyle, or treatment plan. Individual needs may vary, and what works for one person may not be suitable for another.

The Thyroid and Vitamin A