Dementia and Alzheimer's syndrome are becoming a global medical challenge. The World Health Organization (WHO) estimates that more than 57 million people are living with dementia worldwide, and this number is expected to continue to rise rapidly due to the global aging population.
In that context, a new study conducted by scientists at Emory University (USA) has provided a positive signal regarding the ability to improve cognitive health thanks to a very common micronutrient.
The work published in the specialized journal Sleep Medicine surveyed 54 older adults experiencing sleep disorders and mild cognitive impairment, two early warning signs of dementia. The volunteers were assessed for their thinking and memory abilities through a Montreal cognitive test lasting about 10 minutes.
The data analysis results showed that those who used 5,000 international units of vitamin D or more per day scored 13% higher on cognitive tests than the non-user group. This difference remained even after the authors adjusted for indicators related to age, education level, or body mass index.
Notably, the use of vitamin D at lower doses did not bring about clear improvement, and the recorded effectiveness did not depend on the D2 or D3 supplement form.
Associate Professor Victoria Pak at the Nell Hodgson Woodruff School of Nursing at Emory University, a co-author of the study, stated that the stage of mild cognitive impairment combined with sleep disorders is the golden time for intervention.
"Identifying accessible and modifiable factors, such as vitamin D supplementation habits in the early stages of cognitive decline, may become increasingly important, especially as the incidence of Alzheimer's disease continues to rise," said Ms. Pak.
This is not the first time the link between this micronutrient and the brain has been proven. An analytical report on nearly 12,500 older adults published in 2023 noted that the group supplementing with vitamin D had a 40% lower risk of dementia than the non-user group, with this reduction reaching up to 49% in women specifically.
Scientists explain that vitamin D receptors are present in many areas of the brain, participating directly in protecting nerve cells and controlling inflammatory responses that increase with age. Besides that, this micronutrient also contributes to regulating the sleep-wake cycle, addressing the insomnia often encountered in dementia patients.
Although the results are promising, medical experts still offer cautious advice. Expert Sandra Zhang from the Frances Stern Nutrition Center at Tufts Medical Center (USA) notes that a dose of 5,000 international units per day is relatively high compared to the usual recommended requirement of 600 to 800 units.
In addition, expert Jessica Cording, author of the book The Little Book of Game Changers, emphasizes that people should absolutely not self-administer high-dose vitamin D but need to perform blood tests and consult a specialist doctor to be advised on a regimen suitable for their physical condition.
