Vitamin D3

Also known as: Cholecalciferol, D3

Vitamin

Supplement

Tier A

Meta-analysis of RCTs (n>500)

T1Full ProfileDeficiency

Crucial hormone-like vitamin for immune function, mood, bone health, and testosterone. Most people in northern latitudes are deficient.

Mechanism of Action

Functions as a steroid hormone. Regulates calcium homeostasis, immune function, and gene expression via VDR receptors.

Contraindications

Hypercalcemia
Kidney disease (consult physician for dosing)
Sarcoidosis

Performance Profile

Mood

Stress Resistance

Anxiety Reduction

Emotional Stability

Dosage

1000IU

min

4000IU

10000IU

max

Timing

Best time

Morning

1 wk

onset

1 mo

duration

Half-life

2 wk

Safety & Legal

9/10

Well-tolerated

Legal Status

OTC

Mild

Moderate

Severe

Hypercalcemia (overdose)

<0.1%severe

Nausea

<0.1%mild