What is Vitamin D?

Definition: Vitamin D is a fat-soluble vitamin essential for numerous bodily functions, including calcium absorption, bone health, immune system regulation, and thyroid function. It is often referred to as the "sunshine vitamin" because our skin produces it when exposed to sunlight.

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

Vitamin D2 (Ergocalciferol): Found in plant-based sources and fortified foods. It is less potent than D3 and is converted to its active form in the liver and kidneys.
Vitamin D3 (Cholecalciferol): Derived from animal-based sources and produced in the skin upon sun exposure. It is the most effective form for raising and maintaining optimal vitamin D levels.

Daily Requirements for Vitamin D

Infants (0-12 months): 400 IU/day
Children (1-18 years): 600 IU/day
Adults (19-70 years): 600-800 IU/day
Pregnant/Breastfeeding Women: 600-800 IU/day
Elderly (70+ years): 800-1000 IU/day
People with Deficiency or Malabsorption Issues: Up to 5000 IU/day under medical supervision.

What Does Vitamin D Do in Our Body?

Calcium Absorption: Facilitates calcium and phosphorus absorption in the gut, essential for bone health.
Immune Support: Modulates immune responses, reducing inflammation and supporting the body’s defense mechanisms.
Hormonal Regulation: Plays a role in hormone production, including thyroid hormones.
Cell Growth: Supports cellular differentiation and proliferation.

Symptoms of Vitamin D Deficiency

Physical Symptoms: Fatigue, muscle weakness, bone pain, and frequent infections.
Cognitive Symptoms: Depression, memory issues, and mood swings.
Thyroid Symptoms: Worsening of hypothyroid or hyperthyroid symptoms, including hair thinning and weight changes.

What Does Vitamin D Do for Our Thyroid Pathway?

Thyroid Hormone Activation: Enhances the conversion of T4 (inactive thyroid hormone) to T3 (active thyroid hormone) in the liver and other tissues.
Immune Regulation: Helps prevent autoimmune thyroid conditions like Hashimoto’s thyroiditis and Graves’ disease by modulating the immune response.
Thyroid Receptor Sensitivity: Improves the sensitivity of cells to thyroid hormones.

What Does Vitamin D Do for Our Liver?

Detoxification: Supports liver detoxification processes by regulating calcium levels needed for liver enzyme activity.
Hormone Conversion: Facilitates the conversion of T4 to T3, a process primarily carried out in the liver.
Fat Metabolism: Assists in the regulation of fat storage and utilization, indirectly supporting liver health.

What Does Vitamin D Do for Our Gut?

Gut Barrier Function: Enhances the integrity of the gut lining, reducing intestinal permeability or "leaky gut."
Microbiome Balance: Supports a healthy gut microbiome by reducing inflammation and promoting beneficial bacteria.
Calcium Absorption: Facilitates calcium uptake in the intestines, crucial for bone and muscle health.

Physical Ailments That Affect Vitamin D

Chronic Illnesses: Conditions like kidney disease, liver disease, and Crohn’s disease impair vitamin D metabolism.
Obesity: Excess body fat sequesters vitamin D, reducing its availability in the bloodstream.
Aging: Reduced skin production and absorption efficiency in older adults.

Food That Impacts Vitamin D

Enhancing Foods: Fatty fish (salmon, mackerel), egg yolks, and fortified foods like milk and cereals boost vitamin D levels.
Blocking Foods: High-phytate foods (e.g., unsoaked legumes) can reduce absorption of vitamin D and associated minerals like calcium.

Medications That Impact Vitamin D

Negative Impact: Corticosteroids, anticonvulsants, and weight-loss drugs can lower vitamin D levels by interfering with absorption or metabolism.
Positive Impact: Vitamin D supplementation can mitigate the side effects of certain medications on bone health.

Natural Supplements That Negatively Impact Vitamin D

Excessive Calcium: High doses can interfere with vitamin D’s role in calcium-phosphorus balance.
Vitamin A Overload: Excessive vitamin A can counteract vitamin D’s benefits, particularly on bone health.

Heavy Metals That Impact Vitamin D

Lead and Cadmium: Can reduce vitamin D activation in the kidneys and impair bone mineralization.
Mercury: Interferes with vitamin D’s role in immune regulation.

Testing for Vitamin D

25-Hydroxy Vitamin D Test: The most reliable test, measuring the storage form of vitamin D in the blood. Optimal levels are generally between 50-70 ng/mL.

Nutrients Required for Vitamin D Absorption

Magnesium: Essential for converting vitamin D into its active form.
Calcium: Works synergistically with vitamin D for bone health.
Vitamin K2: Directs calcium to the bones, preventing arterial calcification.

Foods High in Vitamin D

Animal-Based: Salmon, tuna, egg yolks, and cod liver oil.
Plant-Based: Fortified orange juice, mushrooms (especially UV-exposed).

A Recipe High in Vitamin D

**Sunshine Salmon Bowl**

Ingredients: 200g wild-caught salmon, 1 cup cooked quinoa, 1/4 green and red bell pepper, 1/2 avocado, lemon juice and olive oil for dressing
Instructions: Grill the salmon with olive oil and serve over quinoa with steamed spinach and sliced avocado. Drizzle with lemon juice for extra flavor.

Other Random Information About Vitamin D

Sun Exposure: Spending 10-30 minutes in midday sun without sunscreen can boost vitamin D levels significantly, depending on skin tone and location.
Genetic Factors: Genetic polymorphisms in the VDR (vitamin D receptor) gene can influence how your body utilizes vitamin D.
Storage: Vitamin D is stored in the liver and fat tissues, making consistent intake important for maintaining levels.

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 D