Vitamin D is often called the "sunshine vitamin" because your skin makes it from sunlight. Yet deficiency is remarkably common — even in sunny countries — and it affects far more than just your bones.
What Vitamin D Does
- Helps your gut absorb calcium, keeping bones and teeth strong.
- Supports immune function and healthy muscles.
- Is linked to mood and energy levels.
How It's Tested
The standard test is 25-hydroxy vitamin D (25-OH D). General guidance:
- Below 20 ng/mL — Deficient.
- 20 to 30 ng/mL — Insufficient.
- 30 to 100 ng/mL — Sufficient.
Why Deficiency Is So Widespread
Indoor lifestyles, sunscreen, air pollution, modest clothing, and darker skin pigmentation all reduce how much vitamin D your skin produces. In South Asia and the Middle East, deficiency rates are strikingly high despite abundant sunshine. Symptoms — fatigue, bone or muscle aches, frequent infections, low mood — are easy to overlook.
Correcting Low Levels
- Sunlight — short, regular sun exposure where safe and practical.
- Diet — oily fish, eggs, and fortified foods.
- Supplements — the most reliable fix; your doctor may prescribe a higher loading dose followed by maintenance.
Don't Overdo It
Vitamin D is fat-soluble, so excessive supplementation can cause toxicity and dangerously high calcium. Retest after a few months rather than taking very high doses indefinitely.
Check Your Vitamin D Result
Upload your report to Lab Lens to instantly see whether your vitamin D is deficient, insufficient, or healthy.