A new study discovered that vitamin D deficiency is associated with poor sleep quality and night-time eating during mid-pregnancy in Singapore.
Circadian rhythms, commonly referred to as our body’s internal clock, is the cycle that instructs our bodies when to sleep, wake, eat, rest and many other physiological processes. Our circadian rhythm is largely governed by environmental signals, particularly light and dark intervals within the 24-hour period. Animal studies have found that disruptions in the circadian rhythm leads to weight gain, impulsivity and slower thinking.
Recent experiments have also found that vitamin D may also influence the circadian clock. Therefore, researchers recently hypothesized that vitamin D may influence circadian rhythms and health related outcomes, specifically sleep quality and eating patterns.
Since both sleep disorders and night-time eating are prevalent among pregnant women, researchers wanted to find out whether pregnant women with low vitamin D levels are more prone to these health hazards than women with healthy vitamin D levels.
The researchers used data from a large prospective cohort called Growing Up in Singapore Towards Healthy Outcomes, in which researchers studied how mothers’ diet and lifestyle during pregnancy affects their babies’ growth and health. A total of 890 pregnant women had their vitamin D levels and sleep quality assessed. The participants also completed a 24-hour dietary recall.
The researchers adjusted for confounding factors, such as ethnicity, age, education, income, body mass index < 14 weeks’ gestation and physical activity. By doing this, researchers could better isolate the relationship between vitamin D levels, sleep and eating patterns.
They found that women with vitamin D deficiency (< 20 ng/ml) had 3.49 times higher odds of poor sleep quality and 1.85 times higher odds of night time eating compared to women with healthy vitamin D levels (p < 0.05).
The researchers stated,
“In conclusion, maternal plasma 25OHD deficiency was associated with poor sleep quality and [night] feeding during the late-second trimester of pregnancy in Singapore.”
They continued, “…Plasma 25OHD concentration may be a biomarker of circadian behavioral status among pregnant women.”
The researchers call for randomized controlled trials or Mendelian randomization studies to investigate whether vitamin D supplementation improves human circadian behavior.
Tovey, A. & Cannell, JJ. Vitamin D deficiency linked to poor sleep quality and night-time eating during pregnancy. The Vitamin D Council Blog & Newsletter, April 21, 2017.