[메디칼업저버 박선재 기자] Studies have shown that vitamin D intake is effective in preventing dementia.
Recently, a Canadian research team announced the results of a study that showed that patients who took vitamin D had a 40% lower risk of developing dementia than those who did not take vitamin D for patients who participated in a cohort study conducted by the National Alzheimer’s Disease Coordinating Center (NACC) in the United States.
The study was published in the medical journal ‘Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring’ on the 2nd.
Does vitamin D intake prevent dementia?
A research team led by Professor Zahinoor Ismail of the University of Calgary, Canada, conducted a study on 12,388 patients with normal cognitive function or mild cognitive impairment (MCI), an average of 71 years or older, among patients participating in the NACC.
The research team assigned 12,388 people to the vitamin D administration group (n=4637) and the non-administration group (n=7751). There were more women in the vitamin D group, and the level of education was higher. On the other hand, there were more depression and MCI patients in the non-administration group.
As a result of the study, it was analyzed that the risk of developing dementia in the vitamin D-administered group was 40% lower than in the non-administered group.
In addition, after 10 years, dementia occurred in 2696 people (21.8%), 679 people (25%) in the vitamin D administration group and 2017 people (75%) in the non-administration group.
Even after adjusting for age, gender, education, race, depression, APOE4, and vitamin D exposure, the association with dementia was significantly related (aHR, 0.60; 95% CI, 0.55 to 0.65; P < 0.001).
The dementia prevention effect of vitamin D was also shown in patients who took calcium vitamin D, vitamin D3 (cholecalciferol), and vitamin D2 (ergocalciferol).
The research team said, “As a result of this study, we were able to confirm who should be given vitamin D supplements. In particular, we have secured evidence that vitamin D supplements should be supplemented before cognitive decline begins.”
There are several loopholes, so be careful in interpreting the results.
Experts raised several questions about the findings of this study.
First of all, the vitamin D effect was remarkable in patients who did not have APOE (apolipoprotein E) ε4, a risk gene for dementia.
Another problem was that there was no data on serum vitamin D levels at the duration, dose, and reference point of vitamin D intake in clinical studies.
Professor Ihab Hajjar of the UT Southwestern Medical Center, USA, who was not involved in the study, pointed out, “Like previous studies, the fact that there is no vitamin D level at the reference point in this study is a problem.”
“It is also important that calcium and side effects may occur if a person with normal vitamin D levels consumes additionally,” he added. “There is still no evidence that vitamin D or supplements can prevent cognitive impairment.”
In response, co-author Dr. Byron Creese of the University of Exeter, USA, said that research is needed to find out whether the results of preventing or delaying dementia by taking vitamin D can be reproduced in clinical practice.
“We are currently investigating this issue further by randomizing vitamin D and placebo in the ongoing VitaMIND study at the university,” Dr. Creese said.