Low vitamin D levels associated with higher risk of dementia
A new study published in the journal Neurology is suggesting that vitamin D may be good for brain health and possibly lower the risk for dementia in older adults. Having higher levels of vitamin D in the blood in middle age was found to be associated with lower levels of tau protein in the brain, which is a sign of dementia.
“These results suggests that higher vitamin D levels in midlife may offer protection against developing these tau deposits in the brain and that low vitamin D levels could potentially be a risk factor that could be modified and treated to reduce the risk of dementia,” said study author Martin David Mulligan with the University of Galway in Ireland.
The study involved 793 people with an average age of 39. None of the participants had dementia and the researchers measured the level of vitamin D in their blood at the start of the study. They had brain scans an average of 16 years later that measured levels of tau and amyloid beta proteins in the brain, which are both biomarkers for Alzheimer’s disease. A high level of vitamin D was defined as greater than 30 nanograms per milliliter (ng/mL) and a low level was less than that number.
A total of 34% of participants had low levels of vitamin D and 5% were taking vitamin D supplements. The researchers took into account other factors that could affect tau levels, such as age, sex and symptoms of depression. The authors caution that the study has some limitations and much more research is needed.
“These results are promising, as they suggest an association between higher Vitamin D levels in early middle-age and lower tau burden on average 16 years later,” Mulligan said. “Mid-life is a time where risk factor modification can have a greater impact.” The authors caution that the study has some limitations and much more research is needed.
Recent studies suggest a strong link between vitamin D and Alzheimer's, with low levels increasing dementia risk by up to 125%. Research indicates that vitamin D supplementation may lower dementia incidence by as much as 40%, particularly when started early. Low vitamin D levels (<50 nmol/L) in the blood have been found to be significantly associated with a higher risk of developing Alzheimer's disease and all-cause dementia.
Vitamin D is believed to help the brain by stimulating macrophages to clear amyloid-beta plaques. However, some studies warn against prolonged, high-dose supplementation in older adults, suggesting it may not benefit those with existing dementia.
Preventing kidney stones
Kidney stones can cause some of the most intense pain people ever experience. Kidney stones not only affect daily life but are also a leading cause of hospital emergency visits. Kidney stones reportedly affect 1 in 11 people in the U.S., and almost half will experience a recurrence. Now, a study published in The Lancet, is providing important new insights into why preventing kidney stones is so challenging, even with strong motivation and daily support.
“The trial results show that despite the importance of high fluid intake to prevent stone recurrence, achieving and maintaining very high fluid intake is more challenging than we often assume for people with urinary stone disease,” said Dr. Charles Scales who is co-senior author of the paper and an associate professor at Duke University in North Carolina. “The challenge of adherence likely contributes to the relatively high rate of stone recurrence in people with this chronic condition.”
This study was rather interesting because of its design. Participants were randomly assigned to receive the standard care or to participate in a behavioral hydration program. The program used Bluetooth-enabled smart water bottles that measured fluid intake, personalized hydration goals (“fluid prescriptions”), financial incentives, reminder texts, and health coaching to encourage people to drink more fluids.
The “fluid prescription” was determined by comparing how much urine a participant typically makes with how much more water they needed to drink to reach a urine output goal of at least 2.5 liters a day. Participants in the program did hydrate more, increasing their average urine output, but the increase wasn’t large enough to lower the rate of symptomatic kidney stone recurrence across the overall group.
The trial enrolled 1,658 adolescents and adults at six U.S. clinical centers (UT Southwestern Medical Center, Washington University in St. Louis, University of Pennsylvania/Children’s Hospital of Philadelphia, University of Washington, Mayo Clinic and Cleveland Clinic). It is the largest behavioral study ever conducted for kidney stone prevention. Scientists followed trial participants for two years after enrollment to collect data.
Researchers noted that the study’s design was the first to measure actual stone recurrence, as opposed to fluid intake or urine output, and used regular surveys and imaging to track whether new stones formed or existing stones grew. Together, the findings highlight how difficult it is for many people to drink large amounts of fluid every day, even with structured support.
The study investigators said it raises questions about the potential need for hydration targets that are more individually tailored, since each person’s hydration needs may differ based on age, size, lifestyle, and health conditions. Further, this new evidence underscores the need to explore new ways to prevent stones, including tailored hydration targets, and strategies to overcome hydration barriers created by work and lifestyle. It is hoped that future therapies will help keep minerals dissolved in the urine.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute. He can be reached at medicalminutes@gmail.com.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute.
