On September 4th, 2010 a massive 7.1 magnitude earthquake struck the New Zealand city of Christchurch.
This initial earthquake caused immense property and infrastructural damage, however no one was severely injured. For the next 15 months nearly 11,000 aftershocks occurred, all within 62 miles of Christchurch.
During this period of aftershocks, a 6.3 magnitude aftershock hit 6 miles southeast of Christchurch on February 22, 2011. The aftershock caused 185 fatalities.
In the midst of these earthquakes, a team of researchers from the University of Canterbury were conducting a randomized controlled trial to determine the effects of monthly vitamin D supplementation on respiratory health.
This trial, called VIDARIS, recruited healthy adults and administered either 200,000 IU of vitamin D3 monthly for two months followed by 100,000 IU per month for 18 months, or a matching placebo to participants.
As part of the study protocol, participants were asked to visit with a researcher each month to conduct a brief interview regarding the trial.
In an effort to help natural disaster experts better understand the factors of stress and anxiety in individuals who recently experienced an earthquake, the researchers modified their questionnaire to obtain information about the Christchurch earthquake four months after the February aftershock.
Natural disasters such as the Christchurch earthquake understandably leaves people in a state of mental instability that includes emotions such as panic, despair, stress and anxiety. Vitamin D may improve mental health due to the presence of vitamin D receptors in the brain and the brain’s ability to locally activate vitamin D.
However, it would be nearly impossible to set up and conduct an RCT on vitamin D supplementation following a natural disaster for ethical reasons.
Therefore, the researchers utilized their ongoing RCT to gain some additional information about how the 308 participants, who voluntarily continued the study after the earthquake, were doing and whether their experience differed between the two groups.
In addition to the standard questionnaire given monthly, the research team asked an additional 14 questions to collect information on property damage, family deaths or injuries, and other personal adverse impacts experienced by each participant.
The researchers were interested in determining whether taking vitamin D supplementation reduced the adverse effects experienced by people after this earthquake.
Here’s what they found:
- Not surprisingly, the reported number of adverse psychological events, such as stress and anxiety, were significantly higher after the earthquake compared to before (P=0.007).
- Both the vitamin D and placebo groups experienced a similar amount of personal loss, injury, and property damage.
- There was no significant differences between the groups in regards to mental wellbeing, such as disturbed sleep (P=0.07), increased anxiety and stress (P=0.99), or loss of concentration (P=0.45).
- The vitamin D group reported experiencing a significantly higher amount of adverse effects on family relationships (P=0.003).
The researchers stated,
“We found no significant association between the receipt of monthly vitamin D supplements and the overall adverse impact score or most specific effects of earthquakes.”
In commenting on the higher amount of adverse effects on family relationships seen in the vitamin D group, they added,
“Although this finding was significant at P<0.05, in the context of a lack of effect of vitamin D on the other stress related outcomes, which might be expected to underpin family relationship stress, it would not be appropriate to conclude that vitamin D increases the likelihood of adverse effects on family relationships.”
The researchers note that they didn’t use a validated scale or questionnaire to assess mental well-being. Additionally, vitamin D levels were not measured and the original study wasn’t designed to specifically look at vitamin D’s effect on natural disaster recovery. Taken together, these limit the study’s results.
As the researchers mention, this study doesn’t confirm that vitamin D would be of no benefit in recovering from a natural disaster. Also, these are large monthly doses, not smaller daily doses and some researchers believe large monthly doses are less likely to see a treatment effect than are smaller daily doses, such as 5,000 IU/day.
Two major factors of natural disasters are displacement and food insecurity. People are forced out of their homes and most often must rely on assisted food programs, and maintaining adequate vitamin D levels becomes much more difficult in this setting.
Initiating a vitamin D supplementation program during periods of stress following natural disasters would be easy and affordable, and may benefit the wellbeing of those recovering from distress. A research team from the same university initiated a free vitamins program to those who were caught in the Alberta floods of June 2013.
The research team notes, at the end of their study, the incredible dedication of the participants and researchers who saw the study through. As mentioned, the participants and staff voluntarily continued the study.
Of all the facets of this study, I believe this is a very important aspect that highlights the commitment of researchers and the general public alike in furthering the understanding of vitamin D effects on health.