Vitamin D Lay Summaries

2014

Low vitamin D during pregnancy increases the risk of depression in new mothers

Keywords: vitamin D, pregnancy, baby blues, postnatal depression

What is already known about this subject:

  • Vitamin D deficiency is becoming more common, and is particularly common in women of childbearing age and during and after pregnancy.
  • There is increasing evidence linking low vitamin D levels with depression, however it is not yet known if low vitamin D is also related to postnatal depression.
  • There is an established link between depression shortly after the birth of a baby (also known as the ‘baby blues’) and postnatal depression in the longer term.  Depression after the birth of a baby is also related to emotional problems in the child.

What this Raine study adds:

  • Vitamin D data from blood samples collected at 18 weeks of pregnancy in Raine participants revealed that women with lower vitamin D levels were more likely to report symptoms of depression at 3 days after delivery.
  • This effect was seen even when season of birth, socioeconomic status and body mass index were taken into consideration.
  • Protecting against vitamin D deficiency during pregnancy is sufficient is a simple, cost-effective and safe method of protecting against the development of postnatal blues and potentially postnatal depression.

Robinson, M., et al. (2014). “Low maternal serum vitamin D during pregnancy and the risk for postpartum depression symptoms.” Arch Womens Ment Health 17(3): 213-219. [publink]

Mothers’ vitamin D levels during pregnancy influence children’s lung health

Keywords: lung function, lung development, vitamin D

What is already known about this subject:

  • While it is known that vitamin D is important for bone health, there is also growing evidence that it is also important for lung health.
  • Studies examining the relationship between maternal vitamin D status and asthma in children have shown inconsistent results.

What this Raine study adds:

  • Lung function testing in Raine children at 6 and 14 years of age and vitamin D levels in blood samples collected from their mothers during pregnancy revealed that higher vitamin D levels in mothers was associated with better lung function in children at 6 years of age.
  • A large number of mothers were vitamin D deficient (35%), and boys whose mothers were vitamin D deficient during pregnancy were more likely to have asthma at 6 years of age.
  • Mothers’ vitamin D levels were not associated with allergies in Raine children, nor were they related to asthma or lung function at 14 years of age.
  • This study provides supporting evidence for a role for vitamin D in lung development before birth and lung health in childhood. Vitamin D deficiency may affect lung growth and increase the risk of respiratory disease.

Zosky, G. R., et al. (2014). “Vitamin D deficiency at 16 to 20 weeks’ gestation is associated with impaired lung function and asthma at 6 years of age.” Ann Am Thorac Soc 11(4): 571-577. [publink]

Few Western Australian adolescents are deficient in vitamin D

Keywords: vitamin D, adolescent

What is already known about this subject:

  • Vitamin D is essential for growing and maintaining strong, healthy bones, and may also help to protect against cardiovascular disease and cancer. Maintaining adequate vitamin D levels is particularly important during adolescence when the bones are rapidly growing.
  • Vitamin D is produced in the skin from sun exposure, and factors that influence sun exposure (such as time spent outdoors) affect vitamin D levels.
  • The factors that contribute to vitamin D deficiency in Australian adults have recently been described, but similar data are not yet available in adolescents.

What this Raine study adds:

  • Vitamin D data from blood samples collected from Raine participants at 14 and 17 years of age found higher vitamin D levels in participants who were Caucasian, who exercised more, had a lower body mass index, a greater calcium intake and a higher family income.
  • The highest vitamin D levels were found in blood samples collected at the end of summer.
  • Very few adolescents were classified as vitamin D deficient, though a substantial proportion had potentially insufficient levels, particularly during winter.
  • There is still debate about what levels of vitamin D should be considered adequate, so it is still not clear if strategies are needed to increase vitamin D levels in Western Australian adolescents.

Black, L. J., et al. (2014). “Vitamin D status and predictors of serum 25-hydroxyvitamin D concentrations in Western Australian adolescents.” British Journal of Nutrition 112(7): 1154-1162. [publink]

Adolescents with vitamin D deficiency are more likely to have non-alcoholic fatty liver disease

Keywords: vitamin D, non-alcoholic fatty liver disease, obesity, risk factors, adolescent

What is already known about this subject:

  • Non-alcoholic fatty liver disease is a condition (unrelated to alcohol use) in which fat builds up in the liver, putting the sufferer at risk of serious liver disease.
  • Vitamin D deficiency is common, and may increase the risk of diseases including diabetes, heart disease and metabolic syndrome.
  • Vitamin D is involved in fat metabolism, and studies in adults suggest it may also be involved in the development of non-alcoholic fatty liver disease; however it is not known if this is also the case in adolescents.

What this Raine study adds:

  • Vitamin D levels measured at 14 and 17 years of age and liver ultrasounds in Raine participants at 17 years of age revealed that the majority of participants with fatty liver disease also had low vitamin D levels (51% were classified as having insufficient vitamin D, and 17% were vitamin D deficient).
  • Associations between vitamin D levels and fatty liver disease were not due to obesity or metabolic problems.
  • It may be useful to screen adolescents at risk of non-alcoholic fatty liver disease for vitamin D levels.

Black, Lucinda J, Peter Jacoby, Wendy Chan She Ping-Delfos, Trevor A Mori, Lawrence J Beilin, John K Olynyk, Oyekoya T Ayonrinde, et al. 2014. “Low Serum 25-Hydroxyvitamin D Concentrations Associate with Non-Alcoholic Fatty Liver Disease in Adolescents Independent of Adiposity.” Journal of Gastroenterology and Hepatology 29 (6) (June): 1215-22. doi:10.1111/jgh.12541. [publink]