Winter and Vitamin D deficiency

Winter and Vitamin D deficiency

It turns out there’s a reason Winter can make us feel a little blue and surprisingly, it’s not caused by Summer withdrawals. Now that the sun has taken a vacation, it’s important to monitor your vitamin D levels so you can stay healthy all year round.

Vitamin D is a fat-soluble vitamin and it plays an important role in maintaining bone health and muscle development. Recent studies also suggest that vitamin D deficiency is associated with depression, rheumatoid arthritis, allergies and autoimmune diseases such as multiple sclerosis (MS).

Vitamin D deficiencies are common among South Australians. A recent longitudinal study shows that the vitamin D levels of approximately 1 in every 4 South Australians sit below the recommended level.1 The study also found that vitamin D deficiencies are more common during Winter.

People who are at higher risk of low vitamin D levels include:

  • People with limited or no sun exposure
  • The elderly
  • People with dark skin
  • People with medical conditions that affect the absorption and process of vitamin D
  • Breastfeeding babies with vitamin D deficient mothers
  • People who wear covering clothing for cultural and religious reasons.

The main source of vitamin D comes from our skin exposure to sunlight. Hence, the amount of vitamin D our body synthesises from sun exposure varies considerably from season to season. For adequate vitamin D synthesis during Winter in Adelaide, sun exposure on arms and legs for approximately 30 minutes is recommended. However, people with darker skin require longer sun exposure to achieve the same vitamin D synthesis.

But you can also absorb vitamin D through our food!

Some foods such as oily fish, egg yolks and UV-irradiated mushrooms contain small amounts of vitamin D. However, it is difficult to obtain sufficient vitamin D from food alone.

Many people with low vitamin D levels do not experience any symptoms, but some people may experience muscle aches and weakness.

Vitamin D levels can be determined with a blood test. Based on your general sun exposure and other risk factors, your doctor will decide whether you require a blood test.

The need for vitamin D supplementation depends on an individual’s risk factors of low vitamin D levels. For many people, it is worth considering vitamin D supplements, especially during Winter.

If you require vitamin D supplements, head in-store and speak to a friendly National Pharmacies pharmacist.


  1. Gill, TK, Hill, CL, Shanahan, EM, Taylor, AW, Appleton, SL, Grant, JF, Shi, Z, Grande, ED, Price, K, Adams, RJ 2014, ‘Vitamin D levels in an Australian Population’, BMC Public Health, <>


The content displayed on this webpage is intended for informational purposes and should be used as a guide only. This information does not replace or substitute professional medical advice, diagnosis or treatment. Information contained on this webpage must be discussed with an appropriate healthcare professional before any action is taken based on the content of this webpage.