India gets a lot of sunshine, yet vitamin D deficiency is very common here. Indoor jobs, covered clothing, pollution and darker skin all reduce how much vitamin D the body can make. This guide explains the signs, the test and what your levels mean.
Why is vitamin D important?
Vitamin D helps the body absorb calcium. This keeps bones and teeth strong. It also supports muscles and the immune system.
Most vitamin D is made in the skin when sunlight falls on it. Only a small amount comes from food, such as egg yolk, fatty fish and fortified milk or oil.
Common symptoms of low vitamin D
Many people with low vitamin D have no symptoms at all. When symptoms do appear, they can include:
- Tiredness and low energy
- Body pain, back pain or bone pain
- Muscle weakness or cramps
- Joint pain
- Getting sick often
- Low mood
- Hair fall
In children, severe deficiency can cause rickets (soft, bent bones). In adults, long-term deficiency can lead to weak bones.
These symptoms can also have other causes. A blood test is the only way to know your vitamin D level.
Who is at higher risk?
- People who work indoors most of the day
- People who cover most of their skin when outdoors
- People with darker skin
- Older adults
- People who are overweight
- Pregnant and breastfeeding women
- People with liver or kidney disease
- People with conditions that affect absorption of food from the gut
- People living in polluted cities, where less sunlight reaches the ground
The vitamin D test
The standard test is called 25-hydroxy vitamin D, or 25(OH)D. It measures the main form of vitamin D stored in your body. It is a simple blood test from a vein in your arm.
Fasting is usually not needed for vitamin D alone. If it is part of a package with sugar or lipid tests, follow the fasting advice for the package.
Vitamin D normal levels
These are commonly used ranges for 25-hydroxy vitamin D:
- Deficient: below 20 ng/mL
- Insufficient: 20 to 29 ng/mL
- Sufficient: 30 to 100 ng/mL
- Possibly too high: above 100 ng/mL
Some reports show results in nmol/L instead of ng/mL. To compare, 1 ng/mL is about 2.5 nmol/L. Ranges differ a little between labs and guidelines, so always use the reference range printed on your report.
Can vitamin D be too high?
Yes. Very high vitamin D usually happens from taking too many supplements, not from sunlight. Too much can raise calcium in the blood and cause nausea, weakness and kidney problems. This is why you should not take high-dose vitamin D on your own. Your doctor will decide the right dose and how long to take it.
How to support healthy vitamin D levels
- Safe sunlight: some time in the sun on your arms and face, several days a week, can help. Avoid sunburn.
- Food: include eggs, fish (if you eat it) and fortified milk or other fortified foods.
- Supplements: only if your doctor advises, after checking your level.
- Retest: your doctor may ask you to repeat the test after some months of treatment.
Vitamin D and calcium
Vitamin D and calcium work together. If your vitamin D is low, your doctor may also check calcium, phosphorus and sometimes parathyroid hormone. These help show the full picture of your bone health.
Frequently asked questions
Is 25 ng/mL vitamin D normal?
A level of 25 ng/mL falls in the "insufficient" range by common guidelines. It is not severe, but your doctor may suggest more sunlight, diet changes or a supplement.
Can I get enough vitamin D from food alone?
It is hard. Very few foods have a lot of vitamin D. Sunlight is the main source for most people, and some may need a supplement as advised by a doctor.
How often should I check vitamin D?
If you are being treated for low vitamin D, your doctor may retest after about 3 months. Otherwise, testing once a year or as part of a routine checkup is common.
Book this test
You can book a vitamin D test with home sample collection, online or on WhatsApp. Book a test, see all tests, or check your report values.
This article is for general information only and is not medical advice. Please talk to your doctor about your symptoms and report.
