Vitamin D is made in your skin when sunlight hits it, with a little from food, and it helps your body absorb calcium for strong bones and muscles. Many Australians still run low, especially in winter or with darker skin, and low levels are linked with tiredness, aches and weaker bones over time. The test measures 25-hydroxy vitamin D, the form that shows your stores. The lab range is 50 to 200 nmol/L, and we aim for 75 to 125 nmol/L. Vitamin D is part of the Vively Baseline Health Check, and eligible members get a Medicare rebate on the lab tests after a short GP telehealth consult.
Check Vitamin D alongside 70+ other markers in Vively's Baseline Health Check.
Every marker in range? Get your $99 back. T&Cs apply.Want to save 25%? Try our 4-Month Reset insteadVitamin D is a fat-soluble vitamin and pro-hormone that plays a central role in bone health, immune function, muscle strength and overall metabolism. Your body makes most of its vitamin D when your skin is exposed to UVB rays from sunlight, with smaller amounts coming from foods like oily fish, egg yolks and fortified dairy. Blood tests measure the storage form, 25-hydroxyvitamin D (25(OH)D), reported in nmol/L in Australia.
Vitamin D is one of the most commonly ordered nutrient tests because deficiency is widespread, even in sunny climates like Australia. In the last national survey (ABS, 2011 to 2012), just under 1 in 4 Australian adults (23%) had vitamin D deficiency, meaning a level below 50 nmol/L. In winter that rose to 36%, and to about half of people in Victoria and the ACT. You can see our own members’ winter 2026 results by state further down this page. You can read more in our guide to vitamin D deficiency in Australia.
Dr Michelle Woolhouse, Vively Medical Director, explains what vitamin D does for bones, muscles, nerves and immunity, why it runs low in some people, the everyday factors that play a part (sun exposure, skin tone, clothing, shift work), why more is not always better, and which markers to read with it. Labs usually call a result above 50 nmol/L adequate, with a common lab range of 50 to 200 nmol/L. Vively's optimal range is 75 to 125 nmol/L.
General information, not medical advice. Talk to your doctor about your own results.
Vitamin D helps your body absorb calcium and phosphate, which are essential for strong bones, healthy teeth and proper muscle function. It also acts on receptors found in almost every tissue in the body, influencing immune function, inflammation, insulin sensitivity, cardiovascular health, mood and even how genes are expressed. Low levels have been linked with osteoporosis, fractures, muscle weakness, recurrent infections and increased risk of chronic conditions.
Because vitamin D touches so many systems, deficiency can quietly contribute to fatigue, low mood, poor recovery and long-term health risks well before any obvious symptoms appear. Checking your level gives you a clear, actionable starting point that is easy to correct with the right approach. It is one of the nutrient markers Vively tracks as part of its baseline health testing.
In Australia, vitamin D is generally interpreted using ranges from the Australian and New Zealand Bone and Mineral Society and Osteoporosis Australia. Below 30 nmol/L is considered deficient (severe below 12.5 nmol/L), 30 to 49 nmol/L is mild deficiency or insufficiency, and 50 nmol/L or above is sufficient for bone health, with levels ideally higher at the end of summer to buffer winter decline. Many clinicians consider an optimal range for wider health benefits to sit around 75 to 125 nmol/L, though this is not an official cut-off.
Levels above 250 nmol/L are considered potentially toxic. Interpretation depends on your age, sex, ethnicity, pregnancy status, medications, chronic conditions and season, so results are best reviewed in context. A single reading is more meaningful when interpreted alongside your history and, ideally, tracked across seasons.
Sun exposure is the biggest driver, and it depends on time of day, season, latitude, cloud cover, sunscreen use and how much skin is exposed. Skin tone matters too, since higher melanin reduces vitamin D synthesis and darker skin needs longer sun exposure to make the same amount. Age also plays a role, with older adults producing less vitamin D in the skin and often having lower dietary intake.
Body composition affects vitamin D, since it is fat-soluble and can be sequestered in body fat, lowering circulating levels in people with obesity. Diet contributes through oily fish, egg yolks, mushrooms exposed to UV light, fortified dairy or plant milks and cod liver oil. Malabsorption conditions such as coeliac disease, inflammatory bowel disease, cystic fibrosis and post-bariatric surgery can also reduce levels.
Liver and kidney health influence vitamin D too, since both organs are needed to activate it. Medications including corticosteroids, anti-epileptic drugs, some antiretrovirals, cholestyramine and orlistat can lower vitamin D. Pregnancy, breastfeeding and season are further important factors, and in Australia levels typically fall in winter and rise across summer.
Mild vitamin D deficiency often has no symptoms, which is one of the main reasons it goes undetected. When symptoms are present, they can include persistent fatigue or low energy, muscle weakness, aches or cramps, bone pain (particularly in the hips, lower back or legs), frequent infections and slow recovery from illness. Some people also notice low mood, brain fog, difficulty concentrating, hair thinning or slow-healing wounds.
In children, severe deficiency can cause rickets, and in adults it can cause osteomalacia (soft, weakened bones). Symptoms are rarely specific to vitamin D, so testing is far more reliable than trying to interpret how you feel. Any persistent symptoms are worth discussing with your GP alongside a full clinical picture.
Low vitamin D is common in Australia and is usually driven by limited sun exposure, which can result from indoor lifestyles, shift work, high SPF sunscreen use, covering clothing or living in southern states. Darker skin tones naturally require more sun exposure to synthesise vitamin D, and older age reduces the skin's ability to produce it. Obesity is another common contributor, since vitamin D is stored in body fat and less is available in circulation.
Malabsorption disorders such as coeliac disease, inflammatory bowel disease and cystic fibrosis, as well as post-bariatric surgery, can significantly reduce vitamin D absorption. Chronic liver or kidney disease impair the activation of vitamin D, and medications such as corticosteroids, anti-epileptic drugs and orlistat can lower levels. Exclusive breastfeeding without vitamin D supplementation is another common cause of low levels in infants.
High vitamin D is far less common than deficiency and almost always related to over-supplementation rather than sun or food intake. Symptoms usually appear when vitamin D causes blood calcium to rise (hypercalcaemia), and can include nausea, vomiting, poor appetite, constipation or abdominal pain. Excessive thirst, frequent urination, muscle weakness, confusion, drowsiness and, in severe cases, kidney stones or an irregular heartbeat may also occur.
These symptoms need prompt medical review, since untreated hypercalcaemia can become dangerous. If you take vitamin D supplements and develop any of these signs, stop supplementation and see your GP.
High vitamin D almost always reflects excessive intake from supplements rather than sun or food. Common causes include taking high-dose supplements without medical supervision, combining multiple supplements that contain vitamin D (such as multivitamins, fish oil and bone health formulas), and prescribed high-dose loading doses without appropriate follow-up. Rare medical conditions such as sarcoidosis, some lymphomas and other granulomatous diseases can also increase conversion of vitamin D to its active form.
Sun exposure and food alone are extremely unlikely to cause toxicity, as the body has natural mechanisms to regulate skin production. This is why testing before starting high-dose supplements and retesting after 8 to 12 weeks is a sensible approach.
A low vitamin D level suggests your body has insufficient supply to support bone, muscle and immune function, and long-term deficiency may increase the risk of osteoporosis, fractures and other health issues. It does not diagnose any single condition on its own, but it is a signal worth acting on, particularly if it is persistent or severe. Mild insufficiency often responds well to safe sun exposure, dietary changes or supplementation.
A very high vitamin D level, particularly above 250 nmol/L, may indicate over-supplementation or an underlying condition affecting vitamin D metabolism. High vitamin D combined with high calcium requires medical review. As with all markers, patterns over time and the context of your other results matter more than any single reading.
Yes, a "normal" vitamin D level does not always rule out other issues. Some people feel symptoms of deficiency (fatigue, muscle aches, low mood) even with a level considered technically sufficient, particularly if other nutrients like iron, B12, magnesium or thyroid hormones are also suboptimal. Symptoms usually have multiple contributors, and vitamin D is only one piece.
Vitamin D testing also has limitations, including seasonal variation, assay differences between labs and biological variability between individuals. A single reading may not capture your year-round pattern, especially if tested at the end of summer versus end of winter. This is why vitamin D is best interpreted alongside related markers and your broader health context.
Vitamin D works closely with calcium, so calcium and ionised calcium are important companions, and phosphate is often checked alongside them. Parathyroid hormone (PTH) typically rises when vitamin D and calcium are low, giving further insight into how well the system is working together. Magnesium is another useful marker, since it is needed to activate vitamin D.
Albumin is worth checking too, as it affects how calcium is measured and reflects nutritional status, and alkaline phosphatase (ALP) can flag bone turnover issues. Because fatigue and low mood often have multiple causes, iron studies, ferritin, B12 and thyroid function tests (TSH, free T4) are frequently checked at the same time. Inflammation markers such as hs-CRP add further context, as covered in our article on how the CRP blood test reveals hidden inflammation, and you can see the full set of markers Vively looks at through our tests page and shop tests page.
Safe, regular sun exposure is the most natural way to support vitamin D, ideally aiming for a few minutes on arms, face and legs most days in summer and longer periods in winter, outside peak UV hours. Including vitamin D-rich foods such as oily fish (salmon, sardines, mackerel), egg yolks, fortified milks and cereals, and UV-exposed mushrooms can help support levels. A daily vitamin D3 (cholecalciferol) supplement may be recommended by your GP or dietitian if your level is low, sun exposure is limited or you have higher needs.
Addressing underlying issues such as malabsorption, obesity or medication effects with your GP can make a significant difference, since simply adding vitamin D without treating the root cause may not lift levels effectively. Retesting after 8 to 12 weeks of any changes is a good way to see how your body is responding. Not every marker can or should be self-optimised, and Vively's how it works page explains how testing, monitoring and dietitian coaching combine to make change practical.
See your GP if your vitamin D is significantly low (below 30 nmol/L) or is not improving with basic changes, or if your level is very high (above 250 nmol/L) or you have symptoms of toxicity. Any symptoms such as bone pain, muscle weakness, frequent fractures, kidney stones, ongoing fatigue or unexplained low mood are worth reviewing with a clinician rather than self-managing.
Clinical input is also important if you have chronic conditions such as osteoporosis, chronic kidney disease, malabsorption, liver disease, sarcoidosis or a history of gastric bypass surgery. Pregnancy, planning pregnancy, breastfeeding, and taking medications known to affect vitamin D or calcium metabolism are all reasons to check in. Vitamin D should not be self-diagnosed based on symptoms alone, as testing is the only reliable way to know your level and the right dose for you.
Vitamin D is one of the nutrient markers included in the Vively Baseline Health Check, alongside metabolic, cardiovascular, liver, kidney, hormonal and inflammation markers, adding up to 70+ biomarkers in total. Rather than looking at vitamin D in isolation, Vively interprets it in context with your other results, symptoms, lifestyle, medications and season. That means a low result is not treated as a one-size-fits-all fix but as a signal to explore what may be contributing to it.
An accredited practising dietitian reviews your results with you one on one, helping you understand what they mean and what changes may support your health goals. Because your markers are retested over time, you can see how sun exposure, nutrition, supplementation and lifestyle are actually shifting your vitamin D and broader health profile. Start at the Vively homepage or explore the full range of tests in the Vively shop.
Among 1,884 Vively members tested in 2024 to 2026, women aged 40 to 49 had a median vitamin D of 71 nmol/L (middle half 58 to 86). Men the same age: 79 nmol/L. The lab range is 50 to 200 nmol/L. A member median is not a target.
The line is the median member at each age. The shaded bands show where most members sit. The dashed red lines are the lab range.
| Group (nmol/L) | Members | Median | Middle 50% | 5th to 95th percentile | Lab range |
|---|---|---|---|---|---|
| Women 18 to 29 | 92 | 73 | 58 to 86 | 30 to 141 | 50 to 200 |
| Women 30 to 39 | 315 | 69 | 54 to 83 | 29 to 109 | 50 to 200 |
| Women 40 to 49 | 388 | 71 | 58 to 86 | 36 to 126 | 50 to 200 |
| Women 50 to 59 | 283 | 72 | 59 to 87 | 39 to 121 | 50 to 200 |
| Women 60 and over | 130 | 78 | 60 to 99 | 45 to 150 | 50 to 200 |
| Men 18 to 29 | 87 | 69 | 53 to 99 | 34 to 154 | 50 to 200 |
| Men 30 to 39 | 201 | 71 | 58 to 88 | 37 to 137 | 50 to 200 |
| Men 40 to 49 | 214 | 79 | 64 to 107 | 40 to 144 | 50 to 200 |
| Men 50 to 59 | 115 | 71 | 60 to 94 | 36 to 149 | 50 to 200 |
| Men 60 and over | 59 | 84 | 70 to 111 | 43 to 149 | 50 to 200 |
Pick your sex and age, then type your result.
What is a normal vitamin D level for my age?
Among 1,884 Vively members (first blood test, January 2024 to October 2026), the median vitamin D for women was 73 nmol/L at 18 to 29, 69 at 30 to 39, 71 at 40 to 49, 72 at 50 to 59 and 78 at 60 and over. For men it was 69 nmol/L at 18 to 29, 71 at 30 to 39, 79 at 40 to 49, 71 at 50 to 59 and 84 at 60 and over.
The lab range is 50 to 200 nmol/L. A member median is not a target or a diagnosis. If your result is outside the range on your report, talk to your GP.
In winter 2026 (June to August), 16% of vitamin D results from 1,303 Vively members were under 50 nmol/L, the bottom of the lab range, and 57% were under 75 nmol/L, the bottom of our optimal range. Victoria had the most low results (23% under 50) and Queensland the fewest (10%).
June to August 2026: 23% of results from Victorian members were under 50 nmol/L, against 10% in Queensland.
| State | % under 50 nmol/L | % under 75 nmol/L | Median (nmol/L) | Members |
|---|---|---|---|---|
| VIC | 23% | 62% | 69 | 332 |
| SA | 18% | 70% | 62 | 56 |
| WA | 14% | 58% | 71 | 160 |
| NSW | 14% | 57% | 70 | 410 |
| QLD | 10% | 44% | 79 | 292 |
Results were higher in summer. From December 2025 to February 2026, 5% of results from 132 members were under 50 nmol/L and the median was 87 nmol/L, against 71 nmol/L in winter. Different members tested in each season, so this shows a pattern across members, not how one person’s level changes.
If your result is under 50 nmol/L, talk to your GP about whether you need a supplement and when to retest. Vitamin D is part of the Baseline Health Check, and members retest every 3 months, so you can see how your own level moves with the seasons.
How to get it: Included in the Baseline Health Check. A GP from our network signs your request after a short telehealth consult, so you don't need to visit your own GP first. See how a blood test without a referral works.
Related tests: Caeruloplasmin, Chromium, Vitamin C, Vitamin B9
Learn more: What your vitamin D results can mean; The best supplements for balancing hormones in Australia
Guide: Vitamin D levels in Australia by age, season and state, with Vively member data.
The Baseline Health Check reads 70+ markers, then your dietitian turns your results into a plan. $99 a month, first test included.
Every marker in range? Get your $99 back. T&Cs apply.