Introduction

Vitamin D2, also known as ergocalciferol, is a form of Vitamin D commonly used to treat and prevent Vitamin D deficiency. It plays an important role in maintaining bone health, supporting immune function, and regulating calcium and phosphorus levels in the body.

What Is Vitamin D2?

Vitamin D2 (ergocalciferol) is a fat-soluble vitamin derived from plant and fungal sources. It is often used in fortified foods and prescription supplements.

• Scientific name: Ergocalciferol
• Source: Plant and fungal origin
• Type: Vitamin D analogue

How Vitamin D2 Works in the Body

Once consumed, Vitamin D2 is converted in the liver to 25-hydroxyvitamin D and then activated in the kidneys. The active form helps:

• Increase calcium absorption from the intestine
• Maintain healthy phosphorus levels
• Support bone mineralization
• Assist immune system regulation

Sources of Vitamin D2

• UV-exposed mushrooms
• Fortified plant-based milk
• Fortified cereals
• Prescription Vitamin D2 supplements

Vitamin D Deficiency & Role of D2

Vitamin D deficiency can lead to weak bones, muscle pain, fatigue, and reduced immunity. Vitamin D2 is often prescribed to correct deficiency, especially in individuals who prefer plant-based options.

Common deficiency symptoms include:

• Bone pain and fragility
• Muscle weakness
• Low immunity and frequent infections
• Fatigue and low mood

Dosage & How to Take Vitamin D2

• Mild deficiency: 800–1000 IU daily
• Moderate deficiency: 50,000 IU weekly (short-term, supervised)
• Maintenance: As advised by a healthcare provider

Vitamin D2 should be taken with meals containing fat for better absorption.

Vitamin D2 vs Vitamin D3

• Vitamin D2: Plant-based, commonly used in prescriptions
• Vitamin D3: Animal-derived or synthesized, more potent and longer-lasting

Safety, Side Effects & Precautions

• Generally safe when taken as prescribed
• Excess intake may cause high calcium levels
• Symptoms of overdose include nausea, weakness, and kidney issues
• Avoid self-medication with high-dose Vitamin D2

Special Populations

• Vegetarians & vegans: Suitable plant-based option
• Elderly: May require monitoring of calcium and kidney function
• Pregnancy: Use only under medical guidance
• Kidney disorders: Requires careful supervision

Frequently Asked Questions

Is Vitamin D2 as effective as Vitamin D3?

Vitamin D2 is effective in raising Vitamin D levels but is generally considered less potent and shorter-acting than Vitamin D3.

Can vegans take Vitamin D2?

Yes. Vitamin D2 is plant-based and suitable for vegans.

Best time to take Vitamin D2?

It is best taken with a meal containing fat, preferably during the day.

Can Vitamin D2 cause toxicity?

Toxicity is rare but possible with excessive doses taken for long periods without supervision.

Is Vitamin D2 safe for daily use?

Yes, when taken within recommended limits and under medical guidance.