Myth or reality: Vitamin D and sleep

People have long debated the correlation between vitamin D and sleep. However, a recent study shows that vitamin D levels may contribute to sleep quality and quantity.

D’s and Zzz’s: The studies

A study of 3068 men aged 68 and older showed that those with low vitamin D had lower sleep efficiency. [1] Among participants, 16 per cent had low levels of vitamin D. To identify the possible influence of vitamin D over sleep, researchers controlled for several other factors, including age, the season of the year, other health conditions, body-mass index, and both physical and cognitive function. They found that low levels of vitamin D were linked to several problems with sleep:

• Low vitamin D increased the likelihood that participants experienced insufficient sleep, sleeping fewer than five hours a night.
• Low levels of vitamin D were linked to lower sleep efficiency scores, as well as a greater chance of scoring below 70 per cent. A healthy sleep efficiency score is generally considered to be 85 per cent or higher.

Another article claims that vitamin D pauses the production of melatonin (the hormone that helps us sleep). This would mean that if taken at night, it could disrupt our ability to get a good night’s rest.[2] Other studies[3] conclude that every human has a ‘sweet spot,’ a certain amount of vitamin D absorption that will result in a good night’s sleep. This suggests that too much or too little vitamin D could result in a restless night.

Myth or reality?

Studies so far are showing that there could be a relationship between vitamin D and getting that good night’s sleep, but not enough data exists to suggest that vitamin D may actually be an effective treatment of a low sleep efficiency score. Until we have more concrete data, it is unknown whether or not vitamin D may actually be able to help us catch our ZZZ’s effectively.

Regardless of the many studies done on vitamin D and sleep, it seems that sleep is better when the body is in good health. Vitamin D is a part of maintaining optimal health and therefore could play a role in a good night’s sleep.