Vitamin D deficiency in Indians — why most of us are low

If you're an office-going urban Indian adult, you probably have low Vitamin D. Studies across Indian cities consistently put deficiency rates between 70% and 90%, even in places with year-round sunshine. The number is high enough that some physicians don't bother testing — they just supplement.

But knowing your level matters, because deficiency is gradable. Mild deficiency needs a small daily supplement. Severe deficiency needs a high-dose loading course followed by maintenance. Testing once tells you which one you need.

What Vitamin D does

Vitamin D is misnamed — it's actually a hormone. Your skin makes it when ultraviolet B (UVB) rays from sunlight hit cholesterol in the skin cells. The liver and kidneys then convert it to the active form, which:

• Helps the gut absorb calcium and phosphorus from food (essential for bones)
• Regulates the immune system
• Affects muscle function
• Has roles in mood and inflammation

Without enough Vitamin D, calcium isn't absorbed well — leading to softer bones, muscle weakness, and a long list of secondary effects.

Why are urban Indians deficient?

Several reasons stacked together:

1. Most office work is indoors. Sun exposure during peak UVB hours (10 AM–2 PM) is minimal for most working adults.
2. Sun avoidance. Tanning is culturally undesirable for many, so people actively shade themselves outdoors.
3. Darker skin needs more sun. Indian skin pigments (melanin) absorb UVB before it reaches the underlying cells. Brown skin needs 3–6 times more sun exposure than lighter skin to make the same amount of Vitamin D.
4. Modest dress. Traditional clothing covering arms and legs reduces skin surface exposed to sun.
5. Pollution. Urban smog filters out UVB.
6. Indian diet has little Vitamin D. No major Indian food is naturally rich in Vitamin D. Fortified milk helps, but most adults don't drink enough.

The result: people who feel "they live in a sunny country" still test deeply deficient.

Symptoms of deficiency

Mild deficiency is usually silent. As levels drop, symptoms appear:

• Bone pain (especially in lower back, hips, legs)
• Muscle weakness, particularly in thighs (difficulty climbing stairs, getting up from squat)
• Frequent infections, especially upper respiratory
• Persistent fatigue
• Hair fall
• Low mood or seasonal depression
• In children: poor growth, delayed walking

Severe deficiency can cause rickets in children and osteomalacia in adults — softened bones that fracture easily.

The test

The right test is 25-Hydroxy Vitamin D (also called 25(OH)D). This is the storage form your body makes and the best single indicator of your overall Vitamin D status.

| Level (ng/mL) | Category | |---|---| | Under 20 | Deficient | | 20–30 | Insufficient | | 30–60 | Adequate | | 60–100 | High end of normal | | Over 100 | Excess |

Most labs (including ours) report in ng/mL. International labs sometimes report in nmol/L (divide by 2.5 to convert).

Treatment

Standard treatment depends on the level:

Severe deficiency (under 20 ng/mL)

A loading course: 60,000 IU once weekly for 8 weeks, then maintenance.

Moderate deficiency (20–30 ng/mL)

60,000 IU once weekly for 4 weeks, then maintenance.

Maintenance (after correction)

2000 IU daily OR 60,000 IU once monthly, indefinitely for indoor-job adults.

Retest

3 months after starting supplementation. Target 40–60 ng/mL — comfortably in the adequate range.

The high-dose loading is taken with a fatty meal — Vitamin D is fat-soluble and absorption is much better with fat.

Can I get enough from sun alone?

In theory yes — 20 minutes of midday sun on arms and face, 3–4 times a week, would supply most adults. In practice almost no urban office-going adult achieves this consistently, especially in cooler months or during monsoon. Most physicians now recommend a low-dose maintenance supplement (2000 IU daily) for all indoor-working adults, year-round.

Can I overdose?

Yes, but it takes effort. Toxicity usually requires sustained intake of 10,000+ IU daily for months. Even high-dose physician-supervised treatment is safe when followed correctly. Don't self-prescribe 60,000 IU weekly indefinitely — get retested at 3 months.

What about food?

Limited natural sources:

• Fatty fish (salmon, sardines, mackerel) — best food source
• Egg yolks — small amount
• Fortified milk (most Indian packaged milk is fortified) — modest amount
• Mushrooms exposed to UV light — modest

Diet alone rarely supplies enough to correct deficiency. Supplements are usually needed.

Bottom line

Test once if you haven't. If deficient, do the loading course and switch to maintenance. Retest in 3 months. After that, annual check is enough.

The cost (₹1,200 for the test, less than ₹100/month for maintenance supplements) is low. The fatigue, bone pain, and low mood that disappear after correcting it are not subtle.