# Vitamin D2 (Ergocalciferol)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/vitamin-d2-ergocalciferol
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-18
**Evidence Score:** 8 / 10
**Category:** Vitamin
**Also Known As:** Ergocalciferol, Vitamin D2, Calciferol, Activated ergosterol, Viosterol, Drisdol, Ergosterol D2

## Overview

Vitamin D2 (ergocalciferol) is a plant-derived form of vitamin D that converts to 25-hydroxyvitamin D2 in the liver. It activates vitamin D receptors to regulate [calcium absorption](/ingredients/condition/bone-health), immune cell function, and [neurotransmitter](/ingredients/condition/cognitive) synthesis.

## Health Benefits

- Supports bone health by aiding [calcium absorption](/ingredients/condition/bone-health), crucial for maintaining bone density and reducing fracture risk. - Enhances [immune function](/ingredients/condition/immune-support) by modulating T-cell responses, potentially reducing infection risk by 20%. - Improves mood and [cognitive function](/ingredients/condition/cognitive) by regulating neurotransmitter synthesis, linked to reduced depression symptoms. - Reduces [inflammation](/ingredients/condition/inflammation) by modulating immune responses, beneficial for autoimmune conditions. - Supports muscle function by regulating calcium and phosphate levels, reducing cramp occurrences. - Promotes cardiovascular health by influencing [blood pressure regulation](/ingredients/condition/heart-health) and reducing arterial stiffness. - Enhances [skin health](/ingredients/condition/skin-health) by promoting cell growth and repair, crucial for maintaining a youthful appearance.

## Mechanism of Action

Vitamin D2 undergoes 25-hydroxylation in the liver by CYP2R1 enzyme, then 1α-hydroxylation in kidneys to form active 1,25-dihydroxyvitamin D2. This active metabolite binds to vitamin D receptors (VDR) in target tissues, forming complexes with retinoid X receptors that regulate gene transcription. It enhances intestinal [calcium absorption](/ingredients/condition/bone-health) by upregulating calbindin-D proteins and modulates immune responses through T-regulatory cell differentiation.

## Clinical Summary

Multiple randomized controlled trials with 500-2000 participants demonstrate vitamin D2 supplementation (1000-4000 IU daily) significantly improves [bone mineral density](/ingredients/condition/bone-health) and reduces fracture risk by 15-20%. Meta-analyses of [immune function](/ingredients/condition/immune-support) studies show 20% reduction in respiratory infections among vitamin D2-deficient individuals. However, some research suggests vitamin D2 is 2-3 times less potent than vitamin D3 at raising serum 25-hydroxyvitamin D levels. Mood improvement studies show modest but consistent benefits in seasonal affective disorder patients.

## Nutritional Profile

- Plant-based form of vitamin D. - Commonly found in fortified foods. - Supports bone and immune health.

## Dosage & Preparation

Typical dosage ranges from 400 IU to 2000 IU per day. Consult a healthcare provider before use.

## Safety & Drug Interactions

Vitamin D2 is generally well-tolerated at doses up to 4000 IU daily, with hypercalcemia occurring rarely above 10,000 IU daily. It may interact with thiazide diuretics, increasing hypercalcemia risk, and reduces effectiveness of calcium channel blockers. Contraindicated in hypercalcemia, kidney stones, and sarcoidosis patients. Pregnancy safety is established at recommended doses (600-800 IU daily), but high doses should be avoided.

## Scientific Research

Research shows that Vitamin D2 can effectively raise vitamin D levels in the blood, though it may be less potent than Vitamin D3 in maintaining those levels.

## Historical & Cultural Context

Vitamin D2 has been used since the early 20th century to prevent and treat rickets and other vitamin D deficiencies, particularly in plant-based diets.

## Synergistic Combinations

Calcium, Magnesium, Vitamin K2, Omega-3 Fatty Acids, Zinc

## Frequently Asked Questions

### What's the difference between vitamin D2 and D3?

Vitamin D2 comes from plants and fungi, while D3 comes from animal sources and sun exposure. D3 is 2-3 times more effective at raising blood vitamin D levels and maintaining them longer than D2.

### How much vitamin D2 should I take daily?

The recommended daily intake is 600-800 IU for most adults, though therapeutic doses of 1000-4000 IU are often used for deficiency. Blood testing can determine optimal individual dosing based on 25-hydroxyvitamin D levels.

### Can vitamin D2 cause side effects?

Side effects are rare at recommended doses but may include nausea, constipation, and weakness at high doses above 4000 IU daily. Excessive intake can cause hypercalcemia, leading to kidney stones and heart rhythm abnormalities.

### How long does it take vitamin D2 to work?

Blood levels of 25-hydroxyvitamin D typically increase within 2-4 weeks of supplementation. However, clinical benefits for bone health and immune function may take 8-12 weeks of consistent supplementation to become apparent.

### Is vitamin D2 suitable for vegans?

Yes, vitamin D2 is derived from UV-irradiated yeast and mushrooms, making it completely plant-based and suitable for vegans. Most vitamin D3 supplements come from sheep's wool, making D2 the preferred vegan option.

### What foods naturally contain vitamin D2?

Vitamin D2 is primarily found in mushrooms, particularly those exposed to sunlight, as well as fortified plant-based foods like cereals, plant-based milks, and some margarines. Fermented foods and certain fungi like maitake and shiitake mushrooms are among the richest natural sources of ergocalciferol. However, vitamin D2 from food sources is generally lower in concentration compared to D3 sources, making supplementation often necessary for adequate intake.

### Does vitamin D2 interact with common medications?

Vitamin D2 may interact with certain medications including corticosteroids, anticonvulsants, and glucocorticoids, which can reduce its effectiveness or increase toxicity risk. Medications like orlistat (a weight-loss drug) can impair fat absorption and reduce vitamin D2 absorption, potentially requiring dose adjustments. If you take prescription medications, consult your healthcare provider before starting vitamin D2 supplementation to avoid adverse interactions.

### Who benefits most from vitamin D2 supplementation?

Individuals with limited sun exposure, those following strict vegan diets, people with malabsorption disorders, and those living in northern climates benefit significantly from vitamin D2 supplementation. Older adults and those at risk for osteoporosis particularly benefit due to vitamin D2's role in calcium absorption and bone health. Individuals with chronic inflammation or mood disorders may also see benefits from adequate ergocalciferol levels, though supplementation should complement—not replace—medical treatment.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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