Vitamin D deficiency is surprisingly common in India, even though most of the country gets plenty of sunshine. Indoor lifestyles, covered skin, air pollution, darker skin tones and diets low in vitamin D all play a part. A simple blood test called 25-hydroxyvitamin D, or 25(OH)D, shows whether your level is low, and your doctor can then advise on sun exposure, food and, if needed, supplements.
Key takeaways
- National data show that a sizeable share of Indian children, adolescents and adults have low vitamin D, with deficiency rising in the teenage years.
- Sunshine alone does not guarantee enough vitamin D; time indoors, clothing, pollution and skin tone all reduce how much your skin makes.
- Many people with low vitamin D have no symptoms, while others notice tiredness, bone pain or muscle weakness.
- The 25(OH)D blood test is the standard way to check your level; results are usually reported in ng/mL or nmol/L.
- Supplements can help when levels are low, but the right amount depends on your test result and health, so take them only on medical advice.
What vitamin D does in the body
Vitamin D helps your gut absorb calcium and phosphorus, the minerals that build and maintain strong bones and teeth. Without enough of it, bones can become thin, soft or brittle over time.
It also supports normal muscle function. In children, severe long-lasting deficiency can cause rickets, where growing bones soften and bend. In adults, it can cause osteomalacia (soft bones) and adds to osteoporosis and fracture risk.
How common is vitamin D deficiency in India?
Estimates vary because studies use different cut-offs, age groups and regions. Even so, the pattern is consistent: low vitamin D is widespread across ages and incomes.
The Comprehensive National Nutrition Survey (CNNS 2016–18), which tested blood samples from children across India, found deficiency (25(OH)D below 12 ng/mL) in about 14% of children aged 0–4, 19% of those aged 5–9 and 24% of adolescents aged 10–19. Many more children fell into the "insufficient" band just above that cut-off.
A 2025 review by the Indian Council for Research on International Economic Relations (ICRIER) and the ANVKA Foundation estimated that roughly one in five Indians is deficient, with higher rates reported in the eastern region. A meta-analysis of studies in pregnant women in India put the pooled prevalence of deficiency at around one in three.
Why is deficiency so common in a sunny country?
Your skin makes vitamin D when it is exposed to ultraviolet B (UVB) rays in sunlight. Several everyday factors in India reduce how much of this actually happens.
Lifestyle and environment
- Time indoors: Office work, long school hours and screens mean many people see little direct sun.
- Covered skin: Full-sleeved clothing and covering the head and body leave little skin exposed.
- Avoiding the sun: Many people avoid sunlight to stay cool or prevent tanning.
- Air pollution: Smog and haze filter out some of the UVB rays the skin needs.
Body and diet factors
- Skin tone: Darker skin contains more melanin, which means it needs more sun exposure to make the same amount of vitamin D.
- Diet: Few foods are naturally rich in vitamin D, and largely vegetarian diets contain even less.
- Weight and age: Obesity is linked to lower levels, and older skin makes vitamin D less efficiently.
- Health conditions: Kidney and liver disease, poor fat absorption (such as coeliac disease) and some medicines can lower levels.
Symptoms of low vitamin D
Many people with low vitamin D feel completely well, which is why it is often picked up only on a blood test. When symptoms do occur, they tend to be vague and build up slowly.
| Possible sign | What you might notice |
|---|---|
| Bone pain | Aching in the lower back, hips, legs or ribs |
| Muscle weakness | Difficulty climbing stairs or rising from a chair |
| Muscle aches or cramps | General aches, often mistaken for overwork |
| Tiredness | Ongoing fatigue without an obvious cause |
| Frequent fractures | Bones breaking after minor falls |
| In children | Delayed walking, bowed legs, poor growth, dental problems |
These symptoms have many other possible causes, including anaemia and thyroid problems. Do not assume vitamin D is the reason; let your doctor investigate.
The 25(OH)D test and what the numbers mean
The 25-hydroxyvitamin D test measures the main form of vitamin D circulating in your blood. It is the most reliable marker of your vitamin D status and needs only a routine blood sample.
Labs may report results in nanograms per millilitre (ng/mL) or nanomoles per litre (nmol/L). To convert, multiply ng/mL by 2.5 to get nmol/L. The ranges below follow those used by the US Food and Nutrition Board, as summarised by the US National Institutes of Health.
| Result (ng/mL) | Result (nmol/L) | What it generally indicates |
|---|---|---|
| Below 12 | Below 30 | Deficiency; linked to rickets and osteomalacia |
| 12 to under 20 | 30 to under 50 | Inadequate for bone and overall health in some people |
| 20 and above | 50 and above | Adequate for most people |
| Above 50 | Above 125 | Potentially too high; may cause harm |
Some laboratories use slightly different cut-offs, so interpret your result with your doctor.
Getting vitamin D from sunlight
Sensible sun exposure is a free, natural way to support your vitamin D level. Short periods of sun on uncovered arms, legs or face, a few times a week, help many people. How much you need depends on skin tone, season, time of day and air quality.
Avoid sunburn and do not stay out so long that your skin reddens or you overheat, especially in Indian summers. Glass windows block UVB, so sitting by a sunny window indoors does not help.
Food sources of vitamin D
Diet alone rarely meets your needs, but it still makes a useful contribution. Good sources include:
- Fatty fish: salmon, mackerel, sardines, tuna and other oily fish such as hilsa contain some vitamin D.
- Egg yolks: whole eggs provide small amounts.
- Fish liver oils: a concentrated source, but best used only on advice.
- Mushrooms exposed to UV light: some mushrooms make vitamin D when exposed to sunlight or UV lamps.
- Fortified foods: look for milk, edible oils, cereals or plant milks labelled as fortified with vitamin D.
Vegetarians have fewer natural options, so fortified foods and sun exposure matter more.
Supplements: only with medical advice
If your test shows low vitamin D, your doctor may recommend a supplement. The right type, amount and duration depend on how low your level is, your age, pregnancy status, weight and other health conditions.
High-dose products are easy to buy in India, but more is not better. Taking too much over time can raise calcium in the blood, which may cause nausea, vomiting, confusion, kidney stones and damage to the kidneys and heart. Sunlight cannot cause vitamin D overdose, but supplements can.
Tell your doctor about any vitamin D you already take, including calcium combination tablets.
When to see a doctor
See a doctor if you have ongoing bone pain, muscle weakness, frequent falls or fractures after minor injuries. Parents should seek advice if a child has bowed legs, delayed walking, poor growth or bone pain.
Get medical help promptly if you take vitamin D supplements and develop persistent nausea, vomiting, excessive thirst, frequent urination, confusion or severe weakness. These can be signs of high calcium levels.
In an emergency, such as severe confusion, fainting or an irregular heartbeat, call 108 or 112 in India.
Frequently asked questions
Can I get enough vitamin D from sunlight in India?
Many people can, but a lot do not because they spend most of the day indoors, cover most of their skin or live in polluted cities. Darker skin also needs more sun to make the same amount. A blood test is the only way to know your actual level.
Who should get a vitamin D test?
Testing is most useful if you have bone pain, muscle weakness, past fractures, osteoporosis or conditions that affect absorption. Pregnant women, older adults and people who rarely go outdoors may also be advised to test.
Is it safe to take vitamin D supplements without a prescription?
It is best to avoid self-treating with high-dose products. Vitamin D builds up in the body, and too much can raise blood calcium to harmful levels. Talk to your doctor, who can recommend a safe amount based on your test result.
Does vitamin D deficiency cause hair fall or tiredness?
Low vitamin D has been linked to fatigue, but these symptoms have many other causes, including iron deficiency, thyroid problems and stress. A doctor can check the likely causes first.
How long does it take to correct low vitamin D?
It varies with how low your level is and the treatment plan your doctor recommends. Levels usually rise gradually over several weeks to a few months. Your doctor may repeat the 25(OH)D test to check progress.
Sources
- Vitamin D: Fact Sheet for Health Professionals – NIH Office of Dietary Supplements
- Vitamin D – NHS
- Serum 25-hydroxyvitamin D and vitamin D deficiency among children and adolescents of India (CNNS analysis) – BMC Pediatrics
- Roadmap to Address Vitamin D Deficiency in India – ICRIER
- Pooled estimate of vitamin D deficiency among pregnant women in India – Journal of Health, Population and Nutrition