New research from the journal BMC Psychiatry found that vitamin D deficiency is very common among elderly psychiatric patients, regardless of which psychiatric disorder they are diagnosed with.
Several observational studies have found an association between vitamin D deficiency and certain psychiatric disorders. Other studies have found relationships between vitamin D deficiency and increased risks for depression or depressive symptoms and between vitamin D deficiency and increased cognitive impairment.
There has been little research on vitamin D status in elderly psychiatric, or psychogeriatric, populations. Researchers in Norway recently conducted a study to help understand vitamin D’s role in psychogeriatric populations.
To do so, they compared the vitamin D levels of psychogeriatric patients to the vitamin D levels of a group elderly people in the general population from the same area. They also compared the vitamin D levels of patients with different psychiatric diagnoses to each other.
A total of 95 psychiatric patients and 104 controls were included in the study. Of the 95 patients, 40 of them had depression as their main diagnosis, 18 had depression as part of other diagnoses, and 37 had other diagnoses that didn’t include depression.
After testing their vitamin D levels and running analyses on the results, the researchers found the following:
- Psychiatric patients had an average vitamin level of 16.2 ng/ml, compared to the control group, whose average level was 26.4 ng/ml. This difference was significant (p < 0.001).
- In the patient group, 68 patients had vitamin D deficiency, compared with only 21 individuals in the control group. This difference was also significant (p < 0.001).
- There was no significant difference between patients that had depression as their main diagnosis, patients that had depression as part of other diagnoses, or patients with another psychiatric diagnosis.
- Grouping the patients into five groups (unipolar depression, bipolar depression, psychosis, dementia, and other diagnoses) instead of three still did not result in a significant difference in vitamin D levels.
The researchers succinctly stated,
“In this study, we found a high prevalence (71.6%) of vitamin D deficiency in elderly psychiatric patients compared with a control group (19.2%). We could not find any difference in vitamin D deficiency between patients in different diagnostic groups.”
One reason for the high percentage of elderly psychiatric patients with vitamin D deficiency could be that their age and mental disorder prevents them doing outdoor activities and exposing themselves to adequate sunlight. This might also explain why there were no differences between the different classifications of psychiatric disorders. On the contrary, vitamin D deficiency could also contribute to the development and severity of mental disorders, although this cannot be confirmed from the study.
The researchers noted that the limited number of participants could result in a false negative in their results. Another limitation in the study was the lack of data on the amount of time spent outdoors, use of vitamin D supplements, or psychiatric symptoms in the control group.
Nonetheless, the researchers advised that elderly psychiatric patients be tested for vitamin D deficiency and that supplementation be initiated to correct for cases of deficiency.
More randomized controlled trials are needed to address the issue of causality in elderly populations with mental disorders.