Vitamin D Deficiency in India — Why Most of Us Are Low Despite the Sun | EVO HOMINUS
Nutrition Science Hub

Living in a sunny country
doesn’t mean you’re getting any vitamin D.

Up to 76% of Indians are vitamin D deficient — in one of the sunniest countries on earth. The reason isn’t a lack of sunshine. It’s glass, sunscreen, indoor working hours, pollution, and skin biology, all quietly cancelling out sun exposure most people assume is “enough.” Here’s the real science, the symptoms most people miss, and what actually closes the gap.

By EVO HOMINUS Nutrition Science Updated July 2026 11 min read
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76%
of Indians estimated deficient or insufficient in vitamin D, including in sunny regions
Pooled Indian population studies, Indian Journal of Endocrinology & Metabolism
0%
of UVB passes through ordinary window glass — sunlight through glass makes no vitamin D at all
Photobiology of vitamin D synthesis, dermatology literature
90%
of an office worker’s daylight hours typically spent indoors on a working weekday
Urban lifestyle and sun-exposure pattern studies, India
600 IU
ICMR-NIN 2020 adult RDA for vitamin D per day
ICMR-NIN Recommended Dietary Allowances, 2020

The sunlight paradox — why “I get plenty of sun” usually isn’t true

Vitamin D synthesis depends on a specific mechanism: UVB radiation striking bare skin, converting a cholesterol derivative in the skin into previtamin D3, which the liver and kidneys then convert into its active form. Miss any part of that chain — the right wavelength, bare skin, enough time, enough frequency — and the sunlight you’re getting produces little to no vitamin D, no matter how bright the day looks.

This is where most people’s assumptions break down. “I live in India, I get plenty of sun” typically describes sunlight seen through a car window, an office window, or a light jacket — none of which count. Ordinary window glass blocks UVB radiation almost completely, while allowing UVA (the wavelength responsible for tanning and skin aging) through freely. You can get sunburned skin without making a single unit of vitamin D, and you can sit in a sunlit room all day and synthesize none either.

“India’s vitamin D deficiency isn’t a sunlight problem. It’s a behavior and biology problem happening in a sunny country.”

Summary of pooled Indian epidemiological findings

Five reasons “I get sun” doesn’t mean “I make vitamin D”

Each factor independently reduces or eliminates UVB-driven skin synthesis

Indoor hours →
↓
Almost no direct skin exposure Most working adults leave home, commute in a vehicle, and spend the entire working day indoors under artificial light — all before and after the sun is even out.
No UVB reaching skin at all
Window glass →
↓
UVB filtered out completely Sitting by a sunny window, or driving with the sun on your arm, feels like sun exposure — but glass blocks the UVB wavelength almost entirely while letting UVA through.
UVB fully absorbed by glass
Melanin →
↓
Reduced synthesis efficiency Melanin acts as a natural sunscreen. Darker skin tones — common across the Indian population — require significantly longer UVB exposure to synthesize the same amount of vitamin D as lighter skin.
Melanin absorbs/scatters UVB
Air pollution →
↓
Less UVB reaching ground level Particulate matter and smog in dense urban centers scatter and absorb UVB before it reaches the ground, meaningfully reducing the vitamin-D-effective portion of sunlight in the country’s most populous cities.
Atmospheric UVB scattering
Coverage →
↓
Sunscreen and clothing block synthesis Sunscreen is designed to block UV radiation — including the UVB needed for vitamin D synthesis — and covering clothing has the same effect. Both are sensible for skin health, but both eliminate the sun exposure people assume they’re getting.
UVB absorption/reflection

None of these factors are unreasonable individually — sunscreen prevents skin damage, indoor work is simply how most jobs function, pollution isn’t a personal choice. But stacked together, they explain why a country that receives sunlight nearly year-round can still have a majority-deficient population.

The symptoms most people miss — because they look like something else

Vitamin D deficiency rarely announces itself clearly. Its most common symptoms overlap heavily with ordinary tiredness, stress, and aging — which is exactly why it goes undiagnosed for years in so many people.

01
Persistent fatigue and low energy Often the first and most commonly reported symptom — frequently dismissed as normal tiredness from work or poor sleep rather than investigated as a nutrient gap.
02
Bone and joint pain, especially lower back and legs Vitamin D is essential for calcium regulation and bone mineralization; chronic low levels are associated with dull, persistent aches that don’t trace back to an injury.
03
Muscle weakness Vitamin D receptors are present in muscle tissue; deficiency is linked to reduced muscle strength and function, particularly noticeable in the legs and during stair climbing.
04
Slower recovery from minor illness Vitamin D plays a role in normal immune function; people with low levels sometimes notice colds and minor infections lingering longer than expected.
05
Mood changes Low vitamin D status has been associated with low mood in observational research, though this relationship is complex and not fully established as causal.

If several of these sound familiar and you can’t point to an obvious cause, a vitamin D blood test is a five-minute, inexpensive way to rule it in or out — far more reliable than guessing from symptoms alone.

Who’s most at risk — and who’s usually fine

Higher risk — worth testing proactively

These factors independently reduce vitamin D synthesis or status

Indoor office workers with limited daylight exposure on working days
People with darker skin tones, who need significantly more UVB exposure for the same synthesis
Older adults — skin becomes less efficient at vitamin D synthesis with age
People who are consistently covered by clothing or sunscreen during daylight hours
People with a higher body fat percentage — vitamin D is fat-soluble and gets sequestered in fat tissue, lowering circulating levels
Residents of high-pollution urban centers where UVB is filtered before reaching ground level

Generally lower risk — still worth a baseline check

Lower risk on paper doesn’t guarantee sufficiency — test to confirm

People with regular, substantial midday outdoor time with meaningful skin exposed
People in rural or coastal areas with genuinely high daily outdoor activity
People already taking a vitamin D supplement consistently at an adequate dose
People who regularly eat vitamin D-fortified foods alongside some sun exposure

Why vitamin D3 and vitamin K2 are usually discussed together

The Mechanism

D3 opens the door for calcium. K2 decides where it goes.

Vitamin D3 (cholecalciferol) increases how efficiently your intestines absorb calcium from food and supplements — that’s its primary, well-established role. But absorption is only half the story: once that calcium is in your bloodstream, something has to direct it to where it’s actually needed. Vitamin K2, specifically the long-acting MK-7 form, activates proteins (osteocalcin and matrix Gla-protein) that guide calcium into bone and away from soft tissue and arterial walls, where its accumulation isn’t wanted.

Taking D3 without K2 means more calcium gets absorbed with less clear direction on where it ends up. This is the reasoning behind pairing the two nutrients in a single formula rather than treating vitamin D as a standalone fix.

Why the source of your D3 matters

Not all Vitamin D3 supplements are the same, and the difference isn’t just marketing. Most commercially available D3 (cholecalciferol) is extracted from lanolin — the grease found in sheep’s wool — which, while chemically identical to other D3 once processed, is an animal-derived ingredient not always disclosed clearly on labels. Vegan alternatives like Vitashine, sourced from lichen, deliver the same active D3 molecule without an animal source, which matters directly for the large vegetarian and vegan population in India who may not realize their “D3” isn’t compatible with their diet.

How EVO HOMINUS addresses this

How EVO HOMINUS Addresses This

Vegan D3. Paired with K2. At 100% RDA, daily.

EVO HOMINUS includes Vitashine® vegan Vitamin D3, sourced from lichen rather than lanolin, at the full ICMR-NIN 2020 adult RDA of 600 IU (15 mcg) — alongside MenaQ7® Vitamin K2 (MK-7) in the same daily capsule, so the calcium D3 helps you absorb has clear direction toward bone rather than being left to soft tissue. It sits alongside a full active B-complex and buffered Vitamin C in a single vegetarian capsule, with no proprietary blends and no rounded doses — exactly what’s on the label is what’s in the capsule.

Vitashine® Vegan D3 MenaQ7® Vitamin K2 100% ICMR-NIN 2020 RDA Methylcobalamin B12 Quatrefolic® Methylfolate Zero Fillers · Vegetarian Capsule
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What to actually do about it

01
Test first — serum 25(OH)D Get a serum 25-hydroxyvitamin D test at any major Indian diagnostic lab — Metropolis, SRL, Dr Lal, Thyrocare. This costs roughly ₹800–1,500 and gives you an exact number rather than a guess based on symptoms.
02
If significantly deficient, follow your doctor’s corrective protocol Doctors commonly prescribe a higher weekly or monthly dose for a defined period to correct a confirmed deficiency, followed by a return to daily maintenance levels. This should be based on your specific test result, not self-prescribed.
03
Get 10–15 minutes of genuine midday skin exposure where practical Direct sun on bare arms and legs, without glass or sunscreen in between, around midday when UVB is strongest — not a guarantee of sufficiency on its own, but a meaningful contributor alongside supplementation.
04
Maintain daily intake with a D3 + K2 supplement For ongoing daily maintenance once any confirmed deficiency is corrected, a consistent daily dose — paired with K2 for proper calcium direction — is the realistic long-term approach, since diet alone rarely closes this gap in a typical Indian eating pattern.
05
Re-test periodically Retesting after 3–6 months of consistent supplementation confirms whether your levels have actually improved, rather than assuming a supplement is working without checking.
Common Questions

Vitamin D deficiency, answered plainly.

Because sun exposure and vitamin D synthesis aren’t the same thing. Most working Indians spend daylight hours indoors, under artificial light or behind glass — and glass fully blocks the UVB wavelength that triggers vitamin D production in skin. Add higher melanin content, sunscreen use, air pollution, and covering clothing, and the result is a population living in a sunny country while functionally getting almost none of the sun exposure that matters. Pooled Indian studies put deficiency prevalence at 70–90%, including in sunny regions.

The most commonly reported symptoms are persistent fatigue, bone and joint pain, muscle weakness, slower recovery from minor illness, and mood changes. Many of these are vague enough that people attribute them to stress or aging rather than a nutrient deficiency, which is part of why it goes undiagnosed for so long.

ICMR-NIN’s 2020 RDA for adults is 600 IU (15 mcg) per day. This is the maintenance level for someone who is not already deficient. If a blood test shows deficiency, your doctor may recommend a higher corrective dose for a defined period before returning to daily maintenance — guided by your actual test result, not a guess.

A serum 25-hydroxyvitamin D [25(OH)D] blood test, available at any major Indian diagnostic lab, is the standard way to check your level. Levels below 20 ng/mL are generally considered deficient and 20–30 ng/mL insufficient, though reference ranges can vary slightly by lab. This is the only reliable way to know your actual status.

It’s difficult. Very few foods naturally contain meaningful vitamin D — fatty fish, egg yolks, and UV-exposed mushrooms are among the only significant sources, and none are dietary staples for most Indians. Fortified foods help marginally but rarely close an existing gap on their own. Sensible supplementation, alongside safe sun exposure where practical, is usually the realistic path.

Most vitamin D3 sold in supplements is extracted from lanolin — sheep’s wool grease — an animal-derived ingredient not always disclosed clearly. Vitashine® is a vegan alternative sourced from lichen, delivering the same active D3 molecule without an animal source — relevant for the large vegetarian and vegan population in India.

D3 increases how much calcium your gut absorbs. K2 (MK-7) activates proteins that direct that absorbed calcium toward bone rather than soft tissue and arteries. Taking D3 without K2 addresses only half of that pathway — which is why they’re commonly paired in one formula.

Indoor office workers with limited daylight exposure, people with darker skin tones, older adults, people consistently covered by clothing or sunscreen, people with a higher body fat percentage (vitamin D is fat-soluble and gets sequestered in fat tissue), and residents of high-pollution urban centers where UVB is filtered out before reaching ground level.

EVO HOMINUS delivers the ICMR-NIN 2020 maintenance RDA (600 IU) of vegan D3 daily, appropriate for general daily support and prevention. If a blood test shows significant existing deficiency, your doctor may prescribe a higher corrective dose separately — EVO HOMINUS is designed for ongoing daily maintenance, not as a replacement for doctor-directed correction of a confirmed severe deficiency.
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