The link between sunshine, vitamin D and low mood – by Mint Nutritionist Claudia Oxford-Gonzalez

Today as I write this article it is officially the shortest day, where sunshine hours for the day are at the shortest of the year. Supposedly from here, we are on the road to longer sunshine days! But let’s be honest, that’s not going to happen just yet huh! And there has been a bit in the news recently about the lack of sunshine hours this winter.

Sunshine hours are measured by the amount of direct sunshine at a particular site. Cloud cover will affect this and with the 2018 winter stacking up to so far be quite a wet cloudy miserable one, the moods also tend to be quite miserable also.

 The skin connection – Sunshine and vitamin D moods (and everything else)

 Vitamin D is a fat-soluble vitamin which can be found in small amounts in sardines, salmon, eggs and mushrooms. But actually we only obtain 10% of our vitamin D intake from food. The other 90% we absorb through our skin from UVB rays. This is why vitamin D is often referred to as the “sunshine” vitamin!

When the UVB rays hit the skin a reaction takes place that converts a specific compound found in the skin into pro vitamin D3. Vitamin D is circulated through the blood for a wee while were it is utilised for different purposes and then after it is able to be stored in the liver and in fatty tissue. When the body needs more, further reactions take place to make the vitamin d active so it can be transported throughout the blood.

So although Vitamin D can be stored well, depending on the body’s need for this vitamin, food intake and sun exposure will impact upon the overall levels and potential for deficiency.

Also different aspects will impact on how well we absorb vitamin D in the skin such as:

  • The time of the day, more vitamin D can be made during the middle of the day
  • The closer to the equator you live the easier it is to get Vitamin D all year round
  • Pale skin makes vitamin D faster than darker skin
  • The more skin you expose the better your chances are of getting more vitamin D
  • Ageing associated with decreased dietary intake of Vitamin D in older adults

Vitamin D is an essential nutrient for the body. It is needed for so many aspects of health such as bone health, neuromuscular function, cardiovascular health, immune function and neurotransmitter function. Because of its varied roles in communication for these different functions, vitamin D is regarded as a hormone.

In terms of low mood, vitamin D is shown to be deficient in people with different types of mood disorders including depression, anxiety, schizophrenia and bipolar disorder. It also plays a big role in seasonal affective disorder, a disorder which affects people in winter months where their mood generally drops but obviously and significantly increases during the longer sunnier months.

Vitamin D receptors can be found in different areas of the brain which are involved in key neuro functions but also vitamin D is shown to be neuro protective. This means that it can help to protect the brain by balancing inflammation within the brain. Neuro inflammation is now known to be one of the key drivers of many mood disorders.

Seasonal Affective Disorder (SAD)

This condition as the name suggests is associated with the seasons, specifically autumn and winter and in New Zealand may be experienced between May through to September. It is a form of depression, with the key difference being that mood improves considerably in the spring and summer months when there is more sunshine. Depression is one of the key signs of SAD however other signs include:

  • General low mood or feeling flat
  • Fatigue
  • Feeling sad with no specific reason
  • Feeling stressed and anxious
  • Sleeping more
  • Not feeling like socialising, losing interest in activities

New Zealand sunshine hours and poor absorption

During winter when there is already a lack of sunshine hours and we tend to rug up with extra layers of merino or stay indoors then we immediately are reducing the absorption of this important vitamin.  It is recommended to have our skin exposed to at least 20 minutes of sunshine each day during winter when the sun is it at its highest peak, so somewhere between 11-2 each day.

If you are anything like me who can’t stand the cold, I would find exposing my skin during a frosty winters day too hard! But for someone like my husband who loves the winter and can be out in a t-shirt on a hard frost…then this is super easy.

There has been much debate in recent years on whether there should be cause for concern regarding deficiency of vitamin D. For the moment, blood testing for Vitamin D from a Clinical Nutrition perspective seems hard to obtain via many medical centres.

However there is hope that this will change. With more studies that are being done here in New Zealand showing increasing evidence of Vitamin D deficiency with calls for public health policy to reflect the need to address these issues, hopefully in the near future it will be much easier to obtain a blood test for this vitamin.

In the meantime – here at Mint Health and Fitness we can arrange for you to have this test done privately. Jane or Claudia can discuss this with you if you would like to be tested.

It is important to be tested, because some people may make Vitamin D better than others and therefore have better stores. Toxicity may occur for a small group of people which could result in a build-up of calcium in the blood which is not great for the body.

If you suspect that you could be vitamin D deficient, why don’t you arrange an appointment with one of our Clinical Nutritionists. We can go over your concerns and arrange for a blood test for you. We can also suggest the right dose of Vitamin D for you and any other supplements to help support your health needs.