Vitamin D deficiency: symptoms, tests, treatment and which doctor to see
Why vitamin D deficiency is common in sunny India, the symptoms it can cause, who should be tested, and how to treat it safely.
Also known as: Hypovitaminosis D; Low Vitamin D; Osteomalacia
What vitamin D deficiency is
Vitamin D helps the body absorb calcium and phosphate from food, which are needed to build and keep strong bones. It also plays a part in how muscles and nerves work. Most of our vitamin D is made in the skin when it is exposed to sunlight; only a few foods contain much of it naturally.
When levels stay low for a long time, the body cannot mineralise bone properly. In children this causes rickets, with soft, bent bones and delayed growth. In adults it causes osteomalacia, with aching bones and weak muscles, and it adds to the bone thinning of osteoporosis, raising the risk of fractures in later life.
Symptoms
Most people with low vitamin D have no symptoms, and it is often found on a blood test done for another reason. When the deficiency is more severe or long-standing, people may notice:
- Bone pain or tenderness, often in the lower back, hips, legs or ribs
- Muscle weakness, especially difficulty climbing stairs or getting up from a chair
- Muscle cramps or aches
- Tiredness
- In children: bowed legs, delayed walking, slow growth or late teething
Tiredness and body ache have many causes, including anaemia, thyroid problems and diabetes. Low vitamin D should not be assumed to be the explanation without a proper assessment.
Why it is common in India, and who is at risk
Living in a sunny country does not mean you make enough vitamin D. Many people spend most daylight hours indoors at work, school or home, travel in closed vehicles, and keep most of the skin covered. Darker skin needs more sun exposure to make the same amount of vitamin D, air pollution filters out some of the sunlight that matters, and vegetarian diets contain few natural sources. Your risk is higher if you:
- Rarely go outdoors in daylight, or keep most of your skin covered
- Are older, or are housebound
- Are pregnant or breastfeeding, or are an exclusively breastfed baby
- Carry extra weight
- Have kidney or liver disease, or a gut condition that affects absorption, such as coeliac disease
- Take certain medicines, including some for epilepsy, tuberculosis or HIV, or long-term steroids
Some packaged milk and edible oils in India are fortified with vitamin D; FSSAI marks fortified foods with a '+F' logo. These help, but they rarely correct an established deficiency on their own.
How it is diagnosed
The standard test is a blood test for 25-hydroxy vitamin D, which reflects your stores over the previous weeks. Laboratories in India report it with ranges for deficiency, insufficiency and sufficiency; your doctor will interpret your result alongside your symptoms and risk factors.
Depending on the situation, your doctor may also check:
- Serum calcium and phosphate
- Alkaline phosphatase, an enzyme that rises when bone is not mineralising properly
- Parathyroid hormone, which rises when calcium absorption is poor
- Kidney and liver function
- Sometimes an X-ray or a bone density (DEXA) scan
Testing everyone routinely is not generally recommended. The test is most useful when you have symptoms, a bone condition, a fracture after a minor fall, or a medical reason for poor absorption. Ask your doctor whether you need it rather than repeating it on your own.
Which doctor to see
A general physician can test for and treat most vitamin D deficiency. An endocrinologist is useful when calcium or parathyroid hormone results are abnormal, when the deficiency does not respond to treatment, or when kidney disease or a malabsorption problem is involved. An orthopaedic surgeon is involved when there are fractures or bone deformities, and a paediatrician looks after children with rickets.
You can find general physicians in Bengaluru or endocrinologists in Bengaluru on The Doctor Index, each with a registration you can check.
Treatment
Treatment aims to restore vitamin D stores and then keep them topped up.
Vitamin D supplements
Vitamin D supplements, usually cholecalciferol (vitamin D3), are the main treatment. They come as daily tablets or drops, weekly or monthly capsules, and sachets, and the doctor will set a schedule that first corrects the deficiency and then maintains it. Injections are used only in particular situations. Calcium supplements are added when your diet is low in calcium or your bones need extra support.
More is not better. Taking high-strength sachets or capsules frequently without supervision, or combining several products that each contain vitamin D, can raise calcium to harmful levels, causing vomiting, confusion, kidney stones and kidney damage. Take vitamin D only as prescribed, and tell your doctor about every supplement and multivitamin you use.
Sunlight exposure and diet
Regular, sensible sunlight exposure on the arms and legs helps keep levels up once they are corrected. How much you need depends on your skin, the season and where you live; avoid burning. Eggs, oily fish such as sardines and mackerel, and fortified milk and oil add a little. People with diabetes, kidney disease or heart problems should ask their doctor before making large changes.
Living with it: follow-up
- A repeat blood test after a course of treatment, at a time your doctor advises
- Calcium and kidney checks for people on long-term or high-strength treatment
- Continuing a maintenance plan if your risk factors remain — low levels often return
- Weight-bearing exercise such as walking, and a diet with enough calcium from milk, curd, ragi and green leafy vegetables
When it is an emergency
Call 112 or 108, or go to the nearest emergency department, for:
- A baby or child with fits, muscle spasms or noisy breathing, which can be caused by very low calcium
- Severe vomiting, confusion, extreme thirst or drowsiness in someone taking high-strength vitamin D, which can mean calcium is too high
- A fracture after a fall, especially of the hip in an older person
Questions to ask at your appointment
- Do I actually need a vitamin D test?
- Could something else explain my tiredness or aches?
- What schedule should I follow, and for how long?
- Do I need calcium as well?
- When should my level be rechecked?
- Should my children or elderly parents be checked or supplemented?
Common questions
Questions people ask
- Why am I low in vitamin D when India is so sunny?
- Because what matters is the sunlight that reaches your skin. Indoor work and study, covered clothing, closed vehicles, darker skin, air pollution and a mainly vegetarian diet all reduce how much vitamin D the body makes or receives.
- Can I take vitamin D supplements without a prescription?
- It is better not to. High-strength products are easy to overuse, and too much vitamin D can raise blood calcium and damage the kidneys. A doctor can check whether you need treatment and set a safe schedule and follow-up.
- How long does it take to correct vitamin D deficiency?
- Levels usually improve over several weeks to a few months of treatment, and bone and muscle symptoms can take longer to settle. Your doctor will decide when to recheck the blood test and when to move to a maintenance plan.
- Is vitamin D deficiency linked to other illnesses?
- Low vitamin D clearly harms bone and muscle health. Links with other conditions, such as diabetes, heart disease and infections, have been studied, but whether supplements prevent them is less certain. Your doctor will advise based on your own health.
This condition is usually assessed by a general physician. Every profile shows the doctor’s registration and what has been checked.
All endocrinology conditions →
Sources
- MedlinePlus, US National Library of Medicine — Vitamin D Deficiency
- NIH Office of Dietary Supplements — Vitamin D fact sheet for consumers
- Food Safety and Standards Authority of India — Food fortification resource centre
- MedlinePlus, National Library of Medicine — Vitamin D Deficiency — Public-domain health-topic summary
Vitamin D deficiency: symptoms, tests, treatment and which doctor to see is original text by The Doctor Index; the compiled source draft was used for research. Source: MedlinePlus, National Library of Medicine. Orphadata Science: Free access data from Orphanet. © INSERM 1999; July 2026 data, CC BY 4.0. This product uses the Human Phenotype Ontology (hp/releases/2026-09-01). Only sources listed for this article apply. Source material has been selected and arranged; HPO definitions are reproduced without alteration. No source organisation endorses this compilation. Köhler S et al. The Human Phenotype Ontology project: linking molecular biology and disease through phenotype data. Nucleic Acids Research 2014;42(D1):D966–D974. doi:10.1093/nar/gkt1026.
General information, not advice about your situation. Errors can be reported through the corrections process. Reference TDI-C-2407.