Melbourne's Chilly Blues: Conquering Winter and Vitamin D Deficiency

Melbourne’s winters are characterised by shorter days and limited sun exposure, as much of our vitamin D is synthesized through the skins contact with UVB light, this can potentially lead to vitamin D deficiency. Vitamin D acts more like a hormone, it interacts with many systems in the body thus its deficiency can result in numerous and complex health impacts physically and mentally.

Vitamin D is crucial for:

The immune system

Vitamin D plays a pivotal role in supporting the immune system; vitamin D deficiency may compromise immune function increasing susceptibility to respiratory infections including the common cold and flu. Interestingly countries further from the equator have increased incidence of autoimmunity associated with vitamin D deficiency.

Mood and mental health

Vitamin D is involved in serotonin regulation, as serotonin is involved in mood regulation, its deficiency is associated with low mood, seasonal affective disorder (SAD), and depressive symptoms

Musculoskeletal system health

Vitamin D deficiency is associated with muscle weakness, and compromised muscle function particularly in the larger muscles of the lower limb. This can impact strength training, sports training, functional mobility and reduced physical function.

Bone health

Vitamin D is essential for calcium absorption; both nutrients are required for optimal bone health. Vitamin D deficiency can result in weakened bones increasing the risk of fractures and increase the risk of developing osteoporosis long term.

Chronic diseases

Vitamin D sub- optimal levels have been associated with the development and perpetuation of several chronic diseases including cardiovascular disease, diabetes, autoimmune diseases, and certain cancers.

Vitamin D levels are impacted by other numerous factors including sun exposure, skin pigmentation, clothing coverage, and dietary intake. Vitamin D levels can be checked via a routine blood test referred by your GP.

Increasing your vitamin D status

Sun exposure

In winter it is typically advised to increase exposure times around midday (10am- 3pm). In summer exposure is best during mid-morning or mid-afternoon (outside peak UV times). However, it is important to balance the need for sunlight exposure to produce adequate vitamin D whilst avoiding increased risk of skin damage from excessive exposure.

Supplementation

Supplementation is recommended where testing indicates it is necessary. Optimal vitamin D status can be achieved or maintained through supplementation during winter months.

Dietary sources

Including foods rich in vitamin D to your diet, these include fatty fish (sardines, cod, swordfish, tuna), eggs and mushrooms, beef liver.