Vitamin D Test


The Vitamin D Test measures the amount of this important nutrient in your blood.

 Vitamin D, like all nutrients, is essential for life. Our bodies need it from our environment (sunlight and food in this case) to function.  Due to its anti-inflammatory, antioxidant, and neuroprotective characteristics, it helps the immune system, muscles, and brain cells to work correctly. Although Vitamin D isn't present naturally in many foods, it can be obtained from fatty fish such as salmon, mackerel and sardines, and fortified milk and cereal.

Higher Vitamin D levels have been linked to improved (ICONs needed):


Brain Health


Heart Health


Immune Health and Support


Bone Health


What we measure

Nicknamed the “sunshine vitamin”, direct sunlight turns molecules in your skin into an active form of Vitamin D, allowing your body to produce it as well (calciferol). The quantity of Vitamin D created by your skin can depend on the hour of the day, skin colour and seasonal changes, typically producing less during the winter months.

Many older persons cannot absorb Vitamin D because they are not exposed to sunlight regularly.

 A blood test is the most accurate way to determine your Vitamin D status. If levels fall below 32 ng/mL, a supplement can easily bring them back to optimal levels. Utilising our innovative home-based blood testing kit, we can analyse multiple blood biomarkers to monitor your Vitamin D levels and give you individualised, science-based, quality solutions for your best health or performance.

Did you know?

Getting enough Vitamin D may also play a role in helping to keep you healthy by protecting against the following conditions and possibly helping to treat them, including:

  • Heart disease and high blood pressure.
  • Infections and immune system disorders.
  • Mood swings and depression.
  • Lack of energy.
  • Falls in older people.
  • Colon, prostate and breast cancer
  • Multiple sclerosis

 Without proper Vitamin D intake, your bones can become soft, thin, and brittle and can lead to osteoporosis in some cases. Getting sufficient Vitamin D through proper supplementation may be required if you do not acquire enough Vitamin D from sunlight or dietary sources.

Optimise your vitamin D levels in three easy steps

1 Measure

Exposure to sunlight, eating vitamin D-rich foods and taking supplements does not guarantee that your blood level will be in the desirable range — it must be measured.

2 Modify

Vitamin D test results will give you the information you need to personalise intake.

3 Monitor

Confirm your Vitamin D level has improved with dietary changes by re-testing every 3-4 months.


Order: Choose the test service you would like. The sample collection kit typically arrives in 3 to 5 days.

Collect Sample: Follow the simple kit instructions to collect your blood sample from the comfort of home. Once you collect your sample, mail it back to our lab using the pre-paid envelope.

Get Results: In 2-4 weeks you will receive an email letting you know your personalised results are ready. You'll also get detailed advice with easy-to-understand graphics for your food, exercise, sleep, supplements, and much more. Take action and track your progress to take your health to new heights.

Vitamin D FAQs

Why do I need Vitamin D?

As with all nutrients, our bodies need vitamin D from the environment (through food or sunlight in this case) to function properly. Vitamin D has a particularly important role in bone health by helping with calcium absorption. This is a very clear relationship as its classic deficiency symptoms are diseases of “soft bones” – rickets in children and osteoporosis and fractures in adults (Bilke DD, 2014). However, with the discovery of vitamin D receptors in virtually every type of cell in the body (Pludowski et al. 2018), we have found that vitamin D affects many other parts of the body, like the immune system (Ginde 2009) and the cardiovascular system (Michaelsson et al. 2010). This combination of health benefits may be why several studies have found that those with higher vitamin D blood levels live better for longer (Garland et al. 2014). So, we need vitamin D to build and keep our bones strong, but also to help the rest of our body work like it should.

How do I get Vitamin D?

Vitamin D3 is the primary raw material to make active and usable vitamin D. It is produced when the body is exposed to sunlight (ultraviolet B radiation sunlight). Our bodies are amasingly efficient when it comes to producing vitamin D3; brief sunlight exposure of the arms and face will enable our body to produce 200 international units (IU) of vitamin D3. The precise amount of vitamin D3 produced will vary depending on factors such as skin type, geographical location, season, and time of the day. Vitamin D can also come from our diet but there are very few foods in nature that contain it. The best sources of Vitamin D in nature are fatty fish like salmon, tuna, mackerel, as well as cheese, mushrooms, apples, egg yolks, sardines and fortified foods. Finally, supplements are a potent source of Vitamin D and raise blood levels effectively.

How much Vitamin D do I need?

It depends! At Neuroptimax Diagnostics we recommend aiming for a Vitamin D blood level >30 ng/mL, but that can be achieved in several ways. Some people may be able to reach this level through exposure to the sun, while some may achieve it through a high-fish diet and fortified foods, and others may take a supplement. Still, most will need a combination of two or three of these. If you go the supplement route, the US Institute of Medicine recommends taking no more than 4000 IU per day on average, but, beyond that, how much supplemental vitamin D you should take depends on your blood level.

The best way to know what you need to do to maintain a desirable blood level of vitamin D is to test regularly and change your habits accordingly. There is a seasonal variability in blood levels depending on your latitude, so your levels could drop during the darkest part of the year and you might want to supplement during that time. On the other hand, during the summer you might get enough through vitamin D through sun exposure and not need any supplemental vitamin D.

What is an optimal Vitamin D level?

There is not yet an agreed upon “optimal” Vitamin D level in the scientific community. This mostly comes from a disagreement on “deficiency” (Taylor C, et al. 2018) vs “optimal” blood levels (Holick MF. 2017) and what endpoint is being considered, i.e. bone health vs. infection risk. At Neuroptimax we recommend aiming for a level of at least 30 ng/mL. The evidence for the 30 ng/mL cut off is demonstrated by Garland et al. 2014 where the hazard ratio for mortality plateaus around 30 ng/mL, by Michaelsson et al. 2010 where the lowest risk for death from all-causes, cancer and cardiovascular disease is at 30 ng/mL, by Ginde et al. 2009 where those with levels >30 ng/mL have the lowest risk of upper respiratory tract infections, and by Miliku et al. 2016 where pregnant women with levels >30 ng/mL were at the lowest risk of preterm birth, as well as babies born with low birth weight and small for gestational age. This seems like an excellent target level for several different populations and health states.

You may notice that none of these outcomes are related to bone health (rickets in kids and osteoporosis/hip fracture risk in adults), the primary health outcome related to a deficiency in Vitamin D. For this endpoint, according to the Institute of Medicine, a serum level of >20 ng/mL is considered sufficient and <12.5 ng/mL is deficient. From Neuroptimax’s perspective, optimal vitamin D levels are considered more from a “whole health” perspective rather than specific to bone health, thus the higher target of at least 30 ng/mL.

When should I take a Vitamin D test?

You can take a Vitamin D test at any time. This test is a long-term stable view of your Vitamin D intake and will not be affected by any short-term dietary or supplementary changes. A test will simply tell you if your diet is delivering enough Vitamin D to maintain an optimal level.

If I am already getting plenty of sunshine and/or taking a Vitamin D supplement, do I even need to test?

Yes! Even those who live in sunnier climates and/or take Vitamin D still might be falling short, because there are so many individual factors that can affect your blood level. The only way to truly know if your diet or environment is delivering what you need is to take a test.

What is your Vitamin D blood test actually measuring?

The “blood” level of vitamin D that we present is equal to the concentration of total vitamin D level in plasma or serum. It is measured from a dried blood spot using an LC/MS method, which is a gold standard technique. We have validated our method of measuring plasma vitamin D levels from a dried blood spot against levels in liquid plasma.

What is the difference between the Vitamin D “reference range” and “desirable range”?

The reference range is provided simply to give an idea of how these values compare to a large number of others taken from a relatively healthy population. The reference range of 20-80 ng/mL refers to the range of blood vitamin D levels from a normal population. When we at Neuroptimax have more of our own vitamin D data, we will create our own reference range encompassing the values from 99% of individuals that we test. Currently, we are utilising the reference range from another dried blood spot testing lab.

The desirable range of 30-50 ng/mL is a “goldilocks” range where we believe most of the health benefit has been realised (as compared to having low levels) and there doesn’t seem to be much extra benefit in having higher levels. Many research studies show that >30 ng/mL is predictive of a lot of good health outcomes (see list below), so we consider it a therapeutic threshold.

Lower risk of overall mortality: People with a blood level of 30 ng/mL and above had a lower risk of mortality (Garland et al. 2014).

Lower risk of cardiovascular disease (CVD) and cancer mortality: Lowest risk for death from all-causes, cancer and CVD in individuals with a vitamin D blood level of at least 30 ng/mL (Michaelsson et al. 2010).

Lower risk for respiratory tract infections: Those with vitamin D blood levels at or above 30 ng/mL had the lowest risk of upper respiratory tract infections (Ginde et al. 2009).

Lower risk of hip fractures and falls: Older individuals who achieved a vitamin D blood level of at least 30 ng/mL had a reduced risk of hip fractures (Bischoff-Ferrari et al 2009).

Lower risk of preterm birth: Pregnant women with levels of at least 30 ng/mL were at the lowest risk of preterm birth, as well as babies born with low birth weight and small for gestational age (Miliku et al. 2016).

The other important thing to consider is what it takes to have very high vitamin D blood levels. For example, a vitamin D blood level of 70 ng/mL may impart more health benefits than a level of 30 ng/mL, but the supplemental dosage required to reach those levels could be very high. On average, for someone with low levels to reach 30 ng/mL, one needs at least 1000-2000 IU/day, and the upper limit is currently set at 4000 IU/day.

These are our recommendations, but we always advise you to consult with your doctor before making any dietary changes, especially if it includes taking high doses of a vitamin D supplement. Many other organisations have their own targets and rationales (Institute of Medicine, Endocrine Society), and you are free to use our Vitamin D test to track your progress towards their recommended target ranges if you wish.