We seem to have hit September & the weather has become autumnal rapidly. The nights are drawing in & the weather is starting to cool which means for many that you will start to feel lethargic & tired. One of the main reasons for this can be a lack of Vitamin D.


When your body receives Vitamin D (from sunlight, food, or supplements), it turns the Vitamin D into a hormone. This hormone is called activated Vitamin D or calcitriol.

The body makes around 90% of the Vitamin D it needs. This can only happen when your skin gets enough direct UV light from sunshine. The other 10% of your Vitamin D intake comes from foods rich in the vitamin. If you don’t get a lot of sunlight, or if you usually stay covered up, a quality Vitamin D supplement may help you.

How does sunlight give us Vitamin D?

When we get sunlight on our skin, our body produces a substance called cholecalciferol. This is then turned into calcidiol and then calcitriol by the liver and kidneys.

There are three ways to get enough Vitamin D: from food sources, from a good Vitamin D supplement, & from exposure to enough sunlight on your skin.

During sunny months, your body might make excess calcidiol. But it won’t go to waste. Any extra will be stored in your body fat as a kind of back up for those grey winter days. Experts think that just 10 minutes of sunlight on your skin is enough to avoid Vitamin D deficiency. So get outside when you can.

Vitamin D2 and D3

The most important forms of Vitamin D for the human body are D3 and (to a lesser extent) D2. Make sure you cover your bases by choosing a quality vitamin supplement and eating some foods fortified with D3.

What does Vitamin D actually do to my body?

Vitamin D is important for a huge number of functions in the body, from supporting strong and healthy bones to maintaining your immune system. Most of your body’s Vitamin D comes from getting enough sunlight on your skin. For many people, this is a challenge, which is why new Government guidelines recommend a daily Vitamin D3 supplement.

It’s also been shown to support the immune system. So taking Vitamin D during the winter months when you may be more likely to feel under the weather could help support your immune system, which is integral in fighting off bugs.

But how does Vitamin D actually work within your body?

What happen when you take your daily Vitamin D3?

When you take a Vitamin D supplement, the vitamin passes from your bloodstream into your liver. From here, it goes to the kidneys where it turns into calcitriol. It is then released back into your bloodstream and can now enter your body’s cells where it attaches to Vitamin D receptors. At this point, it can get to work regulating the minerals calcium and phosphorous. Clever stuff!

In your bones

Vitamin D in your bones helps absorb and store calcium in your skeletal tissue. It regulates the cells which build and maintain bones.

In your kidneys

Vitamin D helps recycle calcium in your kidneys so your bones can reabsorb it. If this didn’t happen, you would lose more of your Vitamin D through urination.

In your digestive system

Vitamin D also gets to work in your intestines. Here, it helps your body absorb the calcium from your healthy diet and from any calcium supplements.

Make sure you get enough Vitamin D in a format which your body can use. Support your diet and lifestyle with a quality daily Vitamin D3 supplement which can be absorbed and digested by your body.