During the winter months, as the dark nights start to set in sometimes we experience a more lethargic attitude to our day. It is well known the winter blues can effect our day to day and in more serious circumstances it leads to anxieties that we can not carry out normal every day routines.

Today Dean Ashton, Owner of Urban Reform; Manchester based personal training business explores why we feel low during those shorter days with limited sunshine, and whether this has a direction correlation with seasonal affective disorder (SAD).

SAD also known as winter depression has a negative effect on an individual’s feelings, thoughts, or behaviours which can impair human function within a day to day routine. The onset of depression is hard to specify the direct cause as many which can stem from genetics, environmental factors, illness or even personality (poor self esteem). SAD is linked to reduced sunlight exposure during the shorter autumn and winter days and is a lot more common than you think, with around 60% of the UK has experienced at least one of the symptoms associated with the seasonal form of depression.

Vitamin D has been widely associated with the essential properties to help elevate our mood states. It is believed that Vitamin D activates serotonin which regulates a wide variety brain functions and behaviours. Low serotonin function may compromise mechanisms involved in maintaining recovery from depression rather than having a primary effect to lower mood in all vulnerable people (Cowen and Browning, 2015).

Why is Vitamin D Important to our mental health?

A human body produces vitamin D as a response to sun exposure. A person can also boost their vitamin D intake through certain foods or supplements. Whilst there are many benefits to vitamin D supplementation such as boosting the immune system, healthy bones and reducing risk of illness, there is research that observes those with low Vitamin D deficiency are more like to experience forms of depression.

Studies have shown a link between vitamin D deficiency and SAD. Researchers behind a 2013 meta-analysis noticed that study participants with depression also had low vitamin D levels. The same analysis found that, statistically, people with low vitamin D were at a much greater risk of depression (Anglin et al, 2013).

The researchers believe that because vitamin D is important to healthy brain function, insufficient nutrient levels may play a role in depression and other mental illnesses.

The question is are we getting enough of Vitamin D?

Vitamin D deficiency has been identified as a global problem. Approximately 14% of the world population has inadequate vitamin D levels, 10% of this population is probably from Manchester (where the sun appears more than England winning World cup finals). This vitamin has been usually associated with bone disorders such as rickets, osteomalacia, and osteoporosis. However, these disorders present only a small part of all the disturbances which can be induced by its deficiency.

How much Vitamin D should we be getting?

Recommendations from the US Institute of Medicine suggest that an average daily intake of 400–800 IU, or 10–20 micrograms, is adequate for 97.5% of individuals, whereas for obese individuals, diabetics and pregnant women this may differ based on the considered intake at the time for that individual.

What Are The Main Sources of Vitamin D?

You can get vitamin D from:

•             Sun exposure.

•             Foods that contain vitamin D.

•             Supplements.

Foods that do contain vitamin D include fatty fish like salmon, as well as fish liver oils.

Egg yolks also contain small amounts, and in some countries milk and cereals are enriched with vitamin D. However, supplements are also widely available, and are both safe and effective.


Low vitamin D concentration is associated with depression which supports the association with reduced sunlight during the Autumn/Winter months and SAD. Although treatments to increase vitamin D therapy are limited a more holistic approaches are considered to support our mood states for more sustainable results.

About the author:

Name: Dean Ashton – owner of Urban Reform Manchester (www.urbanreformfit.co.uk)

Dean holds an MSc in Nutrition and has over 11 years experience as a Personal training and health coach. Working with range of clients from mental services and from low economic backgrounds.

Dean’s ambition is to constantly challenge the misleading and confusing information which is often found in the health and fitness world and instead provide high quality and trusted information which helps people to improve their everyday health.


Cowen PJ, Browning M. What hasserotonin to do with depression? World Psychiatry. 2015;14(2):158-160.

Anglin RE, Samaan Z, Walter SD, et  al. Vitamin D deficiency and depression in adults: systematic review and meta-analysis. Br J Psychiatry. 2013;202(2):100–107.