Vitamin D Supplements Could Help with Sleep Disorders

The Relationship Between Vitamin D and Sleep

The benefits of vitamin D are indisputable and are backed up by a mass of research. Not only is vitamin D essential for calcium absorption and maintaining healthy bones, but it also plays a key role in modulating the immune system. What’s more, recent research has linked deficiencies with lowered sleep quantity and quality.   

Unfortunately, vitamin D deficiencies within the UK are all too common and affect as many as 1 in 5 people. This ‘sunshine vitamin’ is produced when the body is exposed to sunlight, which is why deficiencies are commonly being diagnosed during autumn and winter.

Vitamin D and Sleep Apnea

Interestingly, there has been no prior research linking vitamin D deficiencies to sleep until 2009, meaning that this is a relatively new finding.

A big trigger for further investigation on the topic came from data from the National Health and Nutrition Examination Survey (NHANES). NHANES is a program of studies designed to assess the health and nutrition status of people within the United States through interviews and physical examinations. The data collected from the survey during 2005-2006 revealed a link between lower vitamin D levels and shorter sleep duration.

Since this survey, research has rapidly increased and what’s interesting is that even the largest study to date has in fact confirmed the association between sleep and vitamin D.

This large study monitored blood concentration levels in 3,048 men over the age of 68. The results showed that those with vitamin D levels of 20 ng/mL had double the risk of having a total sleep time of less than 5 hours, in comparison to those with a concentration of 40 ng/mL. The study concluded that sleep quantity and quality worsened in correlation with lower concentrations of vitamin D. ¹

Another very recent 2017 study concluded that blood concentration levels of vitamin D were significantly lower in poor sleepers than in good sleepers. However it’s important to note that this study was conducted on hemodialysis patients, and further research is needed to see if this same effect is seen in health individuals. ²

As a result of this mounting evidence, researchers have hypothesised that the current world epidemic of sleep disorders could in fact be linked to vitamin D deficiencies and that vitamin D blood levels should stay within a narrow range (60-80 ng/mL) in order to see improvement in sleep.

What’s more, vitamin D deficiencies have also been associated with specific such disorders as sleep apnea and restless leg syndrome, both of which are huge contributors to poor sleep quality and daytime fatigue. 

Can a Vitamin D Deficiency Cause Sleep Problems?

The mechanisms for how vitamin D may affect sleep are unclear, however, animal studies have located vitamin D receptors in specific areas of the brain that are thought to regulate sleep.

Another possible explanation could be down to vitamin D’s ability to modulate certain inflammatory molecules. There is evidence linking these inflammatory molecules to sleep regulation. 

How To Get Enough Vitamin D

Our bodies are designed to manufacture vitamin D when our skin is exposed to sunlight, however, the body’s ability to do so, varies from person to person. Therefore there are no current guidelines as to how much sunlight we should receive but is estimated that we spend around 10-15 minutes in the UK summer sun without sunscreen a few times a week.

Winter months are more problematic, especially in the UK due to the short days and lack of light. We, therefore, must rely on food sources of vitamin D such as oily fish, eggs, cheese, and foods fortified with vitamin D such as some dairy products or cereals.   

The government also recommends that everyone over the age of 4 are supplement with 10 micrograms (400IU) each day from October to April. Other population groups may need to supplement all year round.

The issue of vitamin D deficiencies in colder countries is so apparent that it’s now widely recommended that everyone should supplement with vitamin D within winter months.

Want to learn more about Vitamin D? Today's your lucky day. We've written a comprehensive guide to the sunshine Vitamin here, going over its benefits, what happens when you don't get enough, and how to boost your intake especially over the gloomy winter period.

REFERENCES

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4288606/

2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC533157

By Lily Soutter, BSc (Hons) Food & Human Nutrition, Dip ION