Postpartum depression has been associated with delays in infant motor development, which may be due, in part, to the increased cortisol levels in depressive mothers. Low vitamin D status has also been linked to motor development delay.
Sunlight has been shown to improve symptoms of depression, decrease cortisol levels, and improve vitamin D status.
Last month (July 2019), results from a clinical trial assessing whether sunlight and vitamin D supplements could improve delayed early motor development in infants with mothers suffering from postpartum depression were published. In this trial, 229 infants were assigned to one of four groups: 400 IU/day of vitamin D, 1000 IU/day of vitamin D, 400 IU/day of vitamin D plus sunlight, or neither vitamin D nor sunlight. Those in the vitamin D plus sunlight group were further divided into groups based on sunlight style (both mother and infant exposed or only infant exposed) and duration (2-7 hours/week or 7-14 hours/week) while those in the vitamin D groups were further divided into groups for sunlight exposure for the mother only or neither mother nor infant exposed (less than 2 hours/week). As a comparison group for motor development, 120 infants from non-depressive mothers were also included.
What were the findings of the study?
Within 2 days postpartum, infants from depressed mothers had lower motor development scores and increased cortisol levels compared to the infants from non-depressive mothers (P<0.05). As shown on the charts below, infants in the vitamin D (400 IU/day) plus sunlight group had better motor development scores and lower cortisol levels over the next two months compared to infants only taking vitamin D supplements (400 or 1000 IU/day) or the control group (P<0.05).
Infants in the highest sun exposure group (7-14 hours/week) achieved the best scores and had the lowest cortisol levels (P<0.05). Further, mothers who received sunlight exposure had improved depression scores and lower cortisol levels compared to mothers who did not receive sunlight exposure (P<0.05).
These findings indicate that sunlight and vitamin D supplements combined can improve motor development, lower cortisol levels, and improve depressive symptoms. For more information about the health benefits of the sun, check out these previous blog posts.
Are you deficient in vitamin D?
Testing your vitamin D level regularly and taking daily steps to keep it at a target level of 40-60 ng/ml (100-150 nmol/L) is important for all stages of health. Find out your levels today! Log on to the shop (click the link below) to get your tests and see for yourself if your levels can be improved.
Make sure you track your results before and after, about every 6 months!
How can I track my sun exposure and vitamin D levels?
To help you track your sun exposure and vitamin D levels, GrassrootsHealth has created an online tracking system called myData-myAnswers. You can also track your dietary intake and supplement use to see how both sun exposure and vitamin D from food and supplements impact your vitamin D levels. Check it out today!