Fortunately, there are some key food sources of vitamin D.
Season of short days has descended which means getting enough vitamin D can be a challenge for us, but it's essential that we do.
Rhiannon Lambert, nutritionist and author of Re-nourish told The Independent, "Vitamin D is a fat-soluble vitamin that is key for the maintenance of minerals such as calcium and phosphorus."
"It also helps absorb calcium, which plays a vital role in forming and maintaining strong bones," she added.
The main source of vitamin D is the sun -- ultraviolet B radiation from sunlight can be synthesised by vitamin D3, the active form of vitamin D, when exposed on the skin.
Lambert listed four main benefits of vitamin D:
1. It helps absorption of calcium and phosphorus.
2. It strengthens bones.
3. It improves brain development and function.
4. It can reduce inflammation.
Lack of vitamin D can lead to deficiencies such as rickets in children and osteomalacia in adults.
Other deficiencies include common health conditions such as constant coughs and colds, tiredness and fatigue, seasonal affective disorder, poor bone and tooth health and low mood.
Previous study recommended that everyone should get 10 micrograms of vitamin D per day.
However, Lambert points out that, "every person is unique therefore this number can vary slightly per person due to biologically how much your body needs and how much it absorbs."
Fortunately, there are some key food sources of vitamin D:
"Always try to eat a varied, nutritious, vitamin D packed meal containing foods such as salmon, eggs and tofu," noted Lambert, adding that they're also great sources of your macro and micro-nutrients.
Lambert suggests taking supplements may be helpful since vitamin D levels range in the above foods might differ in autumn and winter.
"Nevertheless, supplementation is unique to everyone, and other components such as dosage and ingredients can vary depending on where you buy them and the price," she continued.
"This in itself can lead to consuming more than needed and extra ingredients that aren't great for your body."
She recommends people see a General Practitioner (GP) or nutritionist before prescribing themselves supplements and also asks to get a blood test done to find out our vitamin D levels.