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Vitamin D can improve quality of sleep

The National Sleep Foundation suggests that adequate sleep amounts to seven to eight hours per day, which accounts for one-third of your life on this planet. Factors, such as being ill, age and gender can alter sleep time.

While sleeping, your body goes through a repair process and house cleaning — affecting physiological and psychological health. The sleep-wake cycle is set by our internal circadian clock, brain neurons and hormones produced by the hypothalamus and pineal gland in the brain.

With our fast-paced, time-constrained and stressful lifestyles, it should be no secret that sleep disorders have taken center stage world-wide. According to research — The Association Between Vitamin D Deficiency and Sleep Disorders: A Systematic Review and Meta-Analysis — which appears in the October online journal Nutrients, “previous studies revealed that excessive sleep or sleep deprivation were associated with increased risk of adverse health events, including type II diabetes, hypertension, cancers and all-cause mortality.”

Vitamin D, a fat soluble, hormonal-like vitamin, is derived from the diet, including supplement usage or synthesized by ultraviolet-B (UVB) radiation though sun exposure. Certain times of the year, when people are less exposed to the sun, as well as, certain types of skin color can cause a vitamin D deficiency — unless supplemented.

In addition, adequate vitamin D is hard to achieve from the diet alone unless fortified foods, such as milk or an un-fortified food like, mushrooms, are consumed on a regular basis.

Most people associate vitamin D levels with bone status. However, there is direct link to vitamin D status and immune function.

The vitamin D level is assessed by a blood test that measures 25-hydroxyvitamin D (25(OH)D) — considered as the best indicator of vitamin D status.

Prior research has determined that “vitamin D receptors (VDR) were expressed in brain areas that regulate the sleep–wake cycle, such as the hypothalamus. This evidence indicated that higher vitamin D status was inversely associated with the risk of sleep disorders.”

While some research has been inconsistent, “several large sample epidemiology studies found that dietary intake of vitamin D was related to midpoint of sleep, sleep duration and maintaining sleep.”

Chinese researchers, reporting in the journal Nutrient, used a systematic literature search and review, along with a meta-analysis — a compilation of similar studies — to examine any relationship between vitamin D status and sleep disorders. It was found that low serum 25(OH)D “may be a risk factor for of unhealthy sleep.”

Vitamin D serum values — 10, 20 and 30 ng/mL (nanograms per milliliter) were used as cut-off values in the research. Of note, a value — according to many researchers — of less than 20 ng/mL is considered to be a vitamin D deficiency state, and 30 ng/mL and above (up to 100) would be considered normal, with between 20-30 labeled as insufficient status.

“The results showed that the cut-off value of 20 ng/mL, in accordance with the criteria suggested by the IOM (Institute of Medicine), increased the risk of poor sleep quality nearly 60 percent,” commented the investigators.

The researchers cite an intervention study, which reported that vitamin D supplementation (D3) in veterans at a prescription dosage of 50,000 international units (IU) per week, increased their sleep duration, and another double-blind clinical trial demonstrated that “the use of vitamin D supplementation (50,000 IU/fortnight for eight weeks) facilitated sleep duration and quality in people with sleep disorder.”

As with any meta-analysis, the strength of the data is dependent on many variables, such as number of participants, study design, assessment of sleep criteria, and, if a cross sectional format, there may exist casual relationships versus a randomized, controlled trial.

It’s quite easy to work with your primary care provider to not only assess your current vitamin D status, but also to make an informed choice, under medical supervision, to adjust the results, according to your personal health profile.

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