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Vitamin D3 (Cholecalciferol)

Vitamin Evidence: moderate

Overview

Vitamin D3 (cholecalciferol) is a fat-soluble vitamin produced by the skin during sun exposure and found in fatty fish, fortified dairy, and eggs. It supports calcium absorption, bone strength, muscle function, and immune health. D3 raises blood vitamin D levels more effectively than the D2 form. Adults need 600–800 IU (15–20 mcg) daily; the tolerable upper limit is 4,000 IU (100 mcg) per day. Deficiency is common, particularly in northern latitudes and during winter months.

Dosage

50 mcg · With meal · Take with food

Key Interactions

59 verified interactions found

Vitamin E kann die intestinale Aufnahme von Vitamin D3 beeinträchtigen. Bei kombinierter hochdosierter Supplementierung sollte der Vitamin-D-Spiegel kontrolliert werden.

Hohe Vitamin-E-Konzentrationen können die Aufnahme von Vitamin D3 beeinträchtigen. Beide zeitversetzt einnehmen (mindestens 2h Abstand); bei normaler Supplementierung ist keine klinisch relevante Wechselwirkung zu erwarten.

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Calcium carbonate with vitamin D increases calcium excretion in the body.

Vitamin D3 steigert die Calcium-Aufnahme erheblich; die Kombination mit Calciumcarbonat erhöht die Gesamt-Calciumzufuhr stark. Gesamt-Calciumzufuhr aus Supplementen auf ≤500mg/Tag begrenzen und Gesamtzufuhr inkl. Nahrung prüfen (BfR 2024).

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Melatonin Caution

Melatonin and vitamin D regulate immune function through opposite circadian patterns.

Melatonin und Vitamin D3 wirken im zirkadianen Rhythmus gegensätzlich; beide sind jedoch für die Immunregulation wichtig. Vitamin D3 sollte morgens eingenommen werden, Melatonin abends, um eine Interferenz zu minimieren.

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Melatonin Caution

Vitamin D3 may suppress melatonin production when taken in evening. D3 activates circadian-opposing pathways.

Take Vitamin D3 morning, Melatonin bedtime only.

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Quercetin Caution

Quercetin may work synergistically with vitamin D3 and enhance micronutrient benefits.

Quercetin kann die biologische Aktivität von Vitamin D3 unterstützen. Eine gleichzeitige Einnahme ist unbedenklich; die empfohlene Vitamin-D-Tagesdosis sollte weiterhin eingehalten werden.

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Scientific Sources

Frequently Asked Questions

What is Vitamin D3 (Cholecalciferol) used for?

Vitamin D3 (cholecalciferol) is a fat-soluble vitamin produced by the skin during sun exposure and found in fatty fish, fortified dairy, and eggs.

What is the recommended dosage for Vitamin D3 (Cholecalciferol)?

50 mcg. With meal. Take with food.

Does Vitamin D3 (Cholecalciferol) interact with other supplements?

Vitamin D3 (Cholecalciferol) has 59 verified interactions. Top: Vitamin E (Tocopherol), Calcium Carbonate.

When is the best time to take Vitamin D3 (Cholecalciferol)?

With meal. Take with food.

Is Vitamin D3 (Cholecalciferol) safe to combine with other supplements?

Always check interactions before combining supplements. Use VitalStack to verify your full stack for free.

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Not medical advice. VitalStack is not a medical device. For personalized health recommendations, consult a healthcare provider.