Vitamin D Deficiency Symptoms: Signs and Blood TestsVitamin D deficiency symptoms, graded by evidence: who is at risk in India, what your 25(OH)D result means, and when to see a doctor. Read on.

The signs, and the catch

The signs with the strongest evidence are about bones and muscles. Vitamin D helps the body manage calcium and phosphate, which keep bones, teeth and muscles healthy (NHS, Vitamin D). MedlinePlus lists the symptoms of low vitamin D as bone pain, muscle weakness or aches, soft or deformed bones, and weak bones that fracture (MedlinePlus, Vitamin D test).

When deficiency goes on long enough, bones soften. In children that's rickets; in adults it's osteomalacia (NHS, Vitamin D). Osteomalacia shows up as (MedlinePlus, Osteomalacia):

• Widespread bone pain, especially in the hips.
• Muscle weakness.
• Fractures without a significant injury.
• Low-calcium signs: numbness around the mouth, numbness or tingling in the arms and legs, and muscle spasms or cramps.

The catch: symptoms are a poor guide to your level. In 71 patients seen at a Mumbai hospital's rheumatology clinic with low vitamin D and muscle or bone symptoms (but no osteomalacia), researchers found no link between how low the level was and the symptoms, or between the severity of deficiency and the number of symptoms (Kanekar et al., 2010). It was a small look back through case charts, but the lesson holds: you can't feel your way to a number.

Symptom by symptom

Most "signs of low vitamin D" lists present every symptom as equally certain. They aren't. "Strength" below is our editorial read of the sources linked on this page, not a clinical grade.

Aches and pains

In a Minneapolis primary-care clinic, 150 people aged 10 to 65 with persistent, unexplained muscle and bone pain had their vitamin D checked: 93% were at or below 20 ng/mL, and 28% were at or below 8 ng/mL (Plotnikoff & Quigley, 2003). That shows how common low vitamin D is in people with this kind of pain. It doesn't prove the deficiency caused it, because the study had no pain-free comparison group and didn't test whether vitamin D relieved the pain.

Tiredness

There is one useful trial. 120 otherwise healthy adults (mean age 29) with fatigue and a level below 20 ng/mL got either a single 100,000-unit dose of vitamin D3 or a placebo. After four weeks, fatigue scores fell more with vitamin D, and 72% reported feeling better against 50% on placebo (Nowak et al., 2016). The trial was partly funded by the EMDO Foundation, and the authors report no conflicts. The authors call it a pilot, it was short, and they say the results don't apply to milder insufficiency. Tiredness has many causes, so if it lasts for weeks, read why am I always tired and get checked rather than guessing.

Low mood

Low vitamin D has been linked with depression in observational studies, but a large trial didn't bear it out. In VITAL-DEP, 18,353 US adults aged 50 or older without current depression took 2,000 IU of vitamin D3 a day or a placebo for a median of 5.3 years. Depression risk and mood scores didn't differ between the groups (Okereke et al., 2020). Some authors reported ties to supplement makers (one received research support from a supplement company; another's spouse advises a second supplement company). The trial wasn't limited to people who were deficient, so it can't rule out an effect in them, but it doesn't support low mood as a reliable sign.

Frequent colds

A 2021 meta-analysis found a small protective effect of vitamin D against acute respiratory infections. Its 2025 update, adding new trials including one with 15,804 people, found the effect was no longer statistically significant (odds ratio 0.94, 40 trials, 61,589 participants), and baseline vitamin D status didn't change the result (Jolliffe et al., 2025). The review had no funding; one author reported grants from two vitamin makers, outside this work. "I keep catching colds" isn't good evidence of low vitamin D.

Why it's so common in India

Low vitamin D is very common in India, despite the sunshine. A review of Indian studies by doctors at AIIMS New Delhi found prevalence ranging from 40% to 99%, with most studies reporting 80-90%, across all age groups. Most of those studies used a cut-off of 20 ng/mL, and some used others, which is part of why the numbers vary so much (Aparna et al., 2018).

The best population data comes from a representative survey of 1,403 adults aged 30 and over in the Delhi National Capital Region. The median level was 7.7 ng/mL in urban areas and 16.2 ng/mL in rural ones. In the cities, 71% were below 10 ng/mL (severe deficiency, by the study's definition), against 20% in villages. Living in a city, being a woman and abdominal obesity were each linked to severe deficiency (Praveen et al., 2023). One region, one age band, but it fits the office-worker pattern: commute, desk, home, little sun on skin.

Why it happens:

• Not enough sun on skin. About 90% of the vitamin D we need is made in the skin from the sun's UVB rays, and that is cut by atmospheric pollution, latitude and darker skin pigment (Aparna et al., 2018). Indoor work, covering clothing and strong sunscreen all reduce it too (MedlinePlus, Osteomalacia).
• Darker skin. The NHS names people of south Asian background among those who may not make enough vitamin D from sunlight (NHS, Vitamin D).
• Diet. Few foods contain much vitamin D, and the typical Indian diet generally falls short of the daily requirement (Aparna et al., 2018). Vegetarian diets, avoiding dairy and lactose intolerance are listed as dietary risks (MedlinePlus, Osteomalacia).
• Health conditions and medicines. Kidney failure, liver disease, problems absorbing food (including after some stomach surgery) and certain seizure medicines can all lower vitamin D (MedlinePlus, Osteomalacia).

Your 25(OH)D result, decoded

The test that matters measures 25-hydroxyvitamin D, written 25(OH)D, in your blood. MedlinePlus calls it the most accurate way to see whether you have enough, and it needs no special preparation, though you should tell the doctor about any supplements you take (MedlinePlus, Vitamin D test).

The confusing part: experts don't agree on the cut-offs. The two systems you'll see most (Gibson, Principles of Nutritional Assessment):

Units: results come in ng/mL or nmol/L. To convert, nmol/L = ng/mL × 2.5 (same source). So 20 ng/mL is 50 nmol/L.

Which cut-off is right? Nobody has settled it. The IOM set its lower limit from markers of bone health (Gibson). The US-based Endocrine Society's 2011 guideline used higher targets and suggested testing people at risk of deficiency (Holick et al., 2011). Its newer 2024 guideline, written for people without a specific reason for testing, found no clear evidence for an optimal target level and suggests against routine 25(OH)D testing in that group, including people with darker skin or obesity (Demay et al., 2024). The 2024 guideline doesn't apply to people with an established reason for testing, such as the symptoms and conditions above.

In practice: if you have bone pain, muscle weakness, a fracture from a minor fall, or a condition that affects vitamin D, a test makes sense and your doctor will read it in context. If you feel fine, a test "just to see" is less useful than it looks, and a borderline number is not a diagnosis.

You can't feel your way to a number.

Food and sun, the basics

For most people, the sun is the main source: the skin makes most of the vitamin D we need from UVB light (Aparna et al., 2018). Food helps but rarely covers it. The NHS lists oily fish, red meat, egg yolks, liver and fortified foods as sources (NHS, Vitamin D); the AIIMS review adds that vegetables and grains are poor sources (Aparna et al., 2018). That makes it harder for vegetarians who skip eggs and fortified foods.

How much you need: ICMR-NIN's 2020 RDA for vitamin D is 600 IU a day for adult men and women, up from 400 IU in 2010 (ICMR-NIN, 2020). For healthy adults under 75, the 2024 Endocrine Society guideline suggests against routinely taking more than the recommended intake to lower disease risk (Demay et al., 2024).

The sources we opened don't give a reliable "minutes of sun a day" figure for Indian skin, cities and seasons, so we won't invent one. Our guide to vitamin D rich foods covers foods per serving, sunlight and fortified foods in detail.

A daily 600 IU, not a fix

SILT™ Mornings is a morning drink with vitamin D3 at the adult RDA, alongside other vitamins and gut and focus ingredients. It isn't a way to correct a diagnosed deficiency, and we'd rather you knew its limits.

Each 8.8 g stick has 600 IU vitamin D3 (100% of the ICMR-NIN 2020 RDA), 55 mcg vitamin K2 (menaquinone), 80 mg vitamin C and vitamin B12 at 100% RDA. It also has 80 mg caffeine, 200 mg L-theanine, 1.4 g taurine, 5 g Sunfiber® PHGG fibre, 6 billion CFU of three spore-forming Bacillus species (B. subtilis, B. coagulans and B. clausii, 2 billion each) and 550 mg of digestive-herb extracts (saunf, jeera, ajwain, amla). It has a natural sweetener (stevia) and natural colour, with no added sugar, no maltodextrin and no gluten. Stir one stick into 200-250 ml of room-temperature or cold water (never boiling), any time in the morning. Every dose is printed on the back of the pack, and the pack's %RDA figures follow ICMR 2020 and the FSS (Labelling and Display) Regulations 2020 (SILT pack).

The honest limits:

• 600 IU is a daily-intake amount. If a test shows you're deficient, your doctor sets the dose and re-checks; a daily drink doesn't replace that. We don't claim Mornings reproduces any trial on this page.
• Add up your total. If you already take a vitamin D tablet or sachet, count it with this, and stay within your doctor's advice or the NHS adult limit of 4,000 IU a day. The pack's own direction is 1 stick a day, not to exceed the recommended usage level (SILT pack).
• It contains vitamin K2. If you take a blood thinner such as warfarin, ask your doctor before using SILT Mornings, because it contains vitamin K2 (55 mcg). Vitamin K can affect how warfarin works (MedlinePlus, Warfarin).
• It contains 80 mg caffeine, so it's a morning drink.

If you take regular medicines, especially for thyroid, blood pressure, blood sugar or sleep, ask your doctor first. The pack itself says it is not for medicinal use and not a substitute for a varied diet. We hold individual supplier certificates of analysis for our ingredients, summarised on our science page. The vitamin D3 supplier certificate shows 105,010 IU/g against a 90,000-110,000 IU/g specification, and the K2 supplier certificate shows 1.04% MK-7. What is still pending is the combined vitamin blend certificate and the finished-product NABL lab report, and we'll publish them when they're ready. For how D3 and K2 work together, read our vitamin D3 + K2 guide.

MRP ₹1,125 ₹900 · 15 sticks or ₹1,500 for 30 (MRP ₹2,250)

That's ₹60 a stick, or ₹50 in the 30-stick pack.

Test, don't guess

Bone pain, muscle weakness and easy fractures are the real vitamin D deficiency symptoms; tiredness has limited evidence, and low mood and frequent colds aren't well supported. Low vitamin D is very common in urban India, so if you have those signs or a clear risk factor, ask a doctor about a 25(OH)D test and let them dose it. Don't self-prescribe high doses. For everyday intake, start with vitamin D rich foods and some sun; for supplements, read our vitamin D3 + K2 guide; and if you're vegetarian, check vitamin B12 deficiency too. Evidence, not hype.