Vitamin D3 (Cholecalciferol) — 1.25mg (50,000 IU) | 50 Capsules

Vitamin D3 (Cholecalciferol) — 1.25mg (50,000 IU)

Vitamin D3 (cholecalciferol) is a fat-soluble vitamin that plays a foundational role in calcium metabolism, immune regulation, muscle function, and neurological wellness. Unlike Vitamin D2, Vitamin D3 is the form produced naturally in human skin upon exposure to sunlight, and is the most bioavailable and biologically active form of Vitamin D available as a dietary supplement.

This high-strength 1.25mg (50,000 IU) formulation is intended for use under the guidance of a qualified healthcare practitioner, typically for the correction of clinically confirmed Vitamin D deficiency or for specific therapeutic protocols.

Key Nutritional Roles of Vitamin D3

• Calcium absorption & bone mineralisation — Vitamin D3 is essential for intestinal calcium absorption; without adequate Vitamin D3, the body cannot efficiently absorb dietary calcium, regardless of intake. It plays a central role in bone mineralisation and is required for the maintenance of bone density and structural integrity throughout life.
• Immune system regulation — Vitamin D3 activates the innate immune system and supports the production of antimicrobial proteins. Adequate Vitamin D3 levels are associated with a balanced immune response, reduced inflammatory signalling, and a lower risk of certain infections and autoimmune conditions.
• Muscle function — Vitamin D3 contributes to muscle strength and neuromuscular function. This is particularly relevant for older adults, in whom Vitamin D insufficiency is associated with reduced muscle performance and increased fall risk.
• Neurological & cognitive wellness — Vitamin D3 receptors are expressed throughout the brain. Research suggests a role for Vitamin D3 in supporting cognitive function and neurological wellness, though the mechanisms are still being characterised.
• Metabolic & cardiovascular wellness — Adequate Vitamin D3 levels have been associated in observational research with a reduced risk of certain chronic conditions, including cardiovascular and metabolic disorders.

A Note on the Research

Vitamin D3 has been the subject of extensive research. While observational studies consistently associate adequate Vitamin D status with better health outcomes across multiple domains, randomised clinical trials assessing supplementation have produced mixed results — particularly in populations that are not deficient at baseline. Researchers have noted that study design factors, including dosing, baseline Vitamin D status, follow-up duration, and the form of Vitamin D assessed, may contribute to these inconsistencies. [Reference: PMC10163584]

Vitamin D3 & Vitamin K2

Vitamin D3 and Vitamin K2 work synergistically in calcium metabolism. Vitamin D3 supports calcium absorption from the gut, while Vitamin K2 activates the proteins (osteocalcin and Matrix Gla Protein) that direct calcium to appropriate tissues — bones and teeth — and support its appropriate distribution away from soft tissues. For this reason, Vitamin D3 and Vitamin K2 are commonly taken together in nutritional practice. This is particularly important at higher Vitamin D3 doses.

How to Use

Take as directed by your healthcare practitioner. Typically taken once weekly or as prescribed. Best taken with a meal containing fat (Vitamin D3 is fat-soluble and is best absorbed with dietary fat). Best taken alongside Vitamin K2 for synergistic calcium metabolism support.

Precautions

Important: This is a high-strength Vitamin D3 formulation. Use only under the guidance and supervision of a qualified healthcare practitioner. Regular monitoring of Vitamin D and calcium levels is strongly recommended. Do not use if you have hypercalcaemia, granulomatous conditions (such as sarcoidosis), kidney disease, or are taking medications that affect calcium or Vitamin D metabolism without first consulting your healthcare practitioner. Keep out of reach of children.

Stack This With

• Vitamin K2 (MK-7) — essential synergistic pairing at higher D3 doses for appropriate calcium direction
• Magnesium Glycinate — magnesium is required for Vitamin D activation and works alongside D3 and K2 in bone and metabolic wellness
• Vitamin D3 — 250mcg (10,000 IU) — looking for a lower daily maintenance dose? See our 250mcg option available in 90 or 120 capsules

Related Wellness Guides

• Wellness Hub — explore all herbal and nutritional guides

Content provided for informational purposes only. Not medical advice. Not intended to diagnose, treat, or cure any condition. Consult your healthcare practitioner before commencing any supplement regimen.