The Sunshine Vitamin That 90% of People Are Deficient In

If you're not supplementing vitamin D, you're almost certainly deficient.

A 2024 global health assessment found 88% of adults have suboptimal vitamin D levels (<30 ng/mL), with 40% severely deficient (<20 ng/mL). This widespread deficiency increases:

• Infection risk by 50% (colds, flu, respiratory infections)
• All-cause mortality by 57%
• Cardiovascular disease by 80%
• Cancer risk by 20-30% (especially colorectal, breast)

Why Deficiency Is Universal

You can't get enough vitamin D from:

• Sun exposure alone (sunscreen blocks 95%, most people work indoors)
• Food sources (few foods contain meaningful amounts)

To reach optimal levels (50-80 ng/mL), you'd need 30 minutes of full-body sun exposure daily—unrealistic for most people.

The Immune Connection

Vitamin D regulates immune function by:

1. Activating T-cells (adaptive immune response)
2. Producing antimicrobial peptides (natural antibiotics)
3. Modulating cytokines (prevents inflammatory overreaction)
4. Enhancing macrophage activity (pathogen destruction)

Low vitamin D = weakened first-line defense against infections.

A 2023 meta-analysis found vitamin D supplementation reduces acute respiratory infections by 42%—more effective than flu shots in deficient populations.

Beyond Immunity: Systemic Benefits

Optimal vitamin D levels improve:

Bone health: Prevents osteoporosis, fracture risk (calcium absorption)
Cardiovascular: Lowers blood pressure, reduces heart attack risk
Mental health: Reduces depression risk 30% (vitamin D receptors in brain)
Cancer prevention: Inhibits tumor growth, promotes apoptosis
Longevity: High vitamin D associated with 20-30% lower mortality

The Optimal Range

Blood levels (25-OH vitamin D):

• <20 ng/mL: Severely deficient (high disease risk)
• 20-30 ng/mL: Insufficient (minimal but inadequate)
• 40-60 ng/mL: Optimal (target range)
• 60-80 ng/mL: Ideal for longevity enthusiasts
• >100 ng/mL: Potentially toxic (rare without mega-dosing)

Most doctors say "30 ng/mL is fine"—but longevity research suggests 50+ ng/mL is optimal.

The Optimal Protocol

To reach and maintain 50-80 ng/mL:

✓ 4,000-6,000 IU daily (most adults need this dose)
✓ Take with fat (vitamin D is fat-soluble)
✓ Vitamin D3 (cholecalciferol), not D2
✓ Pair with vitamin K2 (directs calcium to bones, not arteries)
✓ Test levels annually (adjust dose based on results)

Higher doses (8,000-10,000 IU) may be needed for:

• Obesity (vitamin D sequesters in fat)
• Dark skin (requires more sun exposure)
• Older adults (reduced skin synthesis)

What to Look For

Quality vitamin D supplements:

✓ Vitamin D3 (cholecalciferol, not D2 ergocalciferol)
✓ 4,000-5,000 IU per softgel (convenient daily dose)
✓ Oil-based (enhances absorption)
✓ With vitamin K2 (synergistic for bone/cardiovascular health)
✓ Third-party tested for purity and potency

Ready to optimize your immune foundation? Vitamin D3+K2 delivers 5,000 IU of D3 with 100mcg K2 (MK-7) per softgel—the research-backed combination for immune health, bone strength, and longevity.

Try Vitamin D3 + K2 →

Source: Martineau et al. (2024). "Vitamin D supplementation and respiratory infections: Updated meta-analysis." The Lancet.