Have you ever noticed how a few minutes in warm sunshine can completely lift your mood? That gentle lift isn’t just in your head – Vitamin D has something to do with it. This nutrient plays a big role in how we feel and function, but the surprising part is around 1 in 4 Australians are still considered Vitamin D deficient.
When we’re talking about optimal Vitamin D levels (the kind that support everything from mood to metabolism), the numbers may be even higher. So let’s dig into what Vitamin D actually does, why so many of us aren’t getting enough and understand the simple, everyday ways to support your levels naturally.
Here’s what affects our ability to make it:
-
Time of day – UVB rays vary throughout the day.
-
Season + latitude – Winter sun and southern regions mean less UVB exposure.
-
Skin type – Different skin tones absorb sunlight differently.
-
Lifestyle – Indoor work, sunscreen, clothing and shade all reduce exposure.
-
Internal conversion – Vitamin D doesn’t stay “Vitamin D” for long. Your liver and kidneys work together to convert it into its active form (Vitamin D3) and this process depends on nutrients like magnesium and calcium.
So yes... it’s a bit more complex than a walk outside.
What makes Vitamin D so special?
Vitamin D may be best known as the “sunshine Vitamin”, but its influence reaches far beyond a healthy glow. Once produced in the body, it acts more like a hormone, quietly supporting a wide range of essential processes. It plays a key role in keeping bones and teeth strong by regulating calcium levels, while also supporting balanced mood and emotional wellbeing. Vitamin D helps the body manage blood sugar more effectively, supports healthy insulin sensitivity, and plays an important role in calming inflammation and regulating immune function. It’s also involved in fertility for both men and women, as well as neuromuscular health, helping muscles contract smoothly and supporting coordination and strength.
What low Vitamin D can look like
Because Vitamin D is involved in so many systems, low levels don’t always show up in obvious ways. Deficiency can subtly affect the body over time, contributing to bone and skeletal issues such as osteoporosis, changes in mood, nervous system function and memory, and an increased risk of autoimmune conditions.
Research has also linked low Vitamin D to metabolic and cardiovascular concerns, certain inflammatory gut conditions, and skin issues like atopic dermatitis. In more complex cases, inadequate levels have been associated with fertility challenges and a higher risk of some cancers. This wide-reaching impact is why testing is so important—many people don’t realise their levels are low until symptoms become harder to ignore.
Why this matters
Balancing safe sun exposure with Vitamin D needs is key. With mindful timing, even a short daily dose can help keep your levels optimal supporting mood, immunity, metabolism and overall health.
Vitamin D rich foods
Because Vitamin D is fat-soluble, it naturally hangs out in foods with healthy fats. Some of the best sources include:
- Oily fish: salmon, sardines, mackerel, tuna (wild-caught is ideal)
- Egg yolks
- Raw dairy: milk, cheese
- Cod liver oil
- Sun-exposed mushrooms
Note – Food is a wonderful supplement to sunshine, but for many people it’s still tricky to reach optimal levels, especially in winter or if you’re mostly indoors.
Testing + supplementation
Getting your Vitamin D checked is one of the simplest and most valuable blood tests you can do for understanding your overall health. It’s especially useful as we move out of winter, when many of us see our levels dip. In fact, in Australia, around 31% of adults have Vitamin D levels considered low, and almost three-quarters don’t reach optimal levels.
Age also plays a role–older skin naturally produces less Vitamin D, so it’s something to be mindful of as we get older.
According to Australian health guidelines, a Vitamin D level of 50 nmol/L or higher is considered adequate for bone and general health, though many experts suggest that slightly higher levels may support extra benefits like mood, immunity and muscle function.
If your levels are on the lower side, a high quality Vitamin D supplement can help, but it’s always best to chat with a healthcare practitioner. They can guide you on the right dose, how often to take it and when to re-test, taking into account your lifestyle, age and the time of year.
