One of the most frightening aspects of Alzheimer’s disease and other dementias is that there is no known cure, and even the best of treatments can only slow the inexorable cognitive decline. However, with new research, we learning what factors can speed the progress of the illness. While we still have no way of stopping the disease yet, there are actions we can take that can delay the onset of conditions.
According to David S. Knopman, M.D. of the Mayo Clinic, “new research suggests people with very low levels of vitamin D in their blood, known as vitamin D deficiency, are more likely to develop Alzheimer's disease and other forms of dementia.” Additionally he points to a study published in Neurology in 2014 which found that “results confirm that vitamin D deficiency is associated with a substantially increased risk of…dementia and Alzheimer disease.”
The obvious question here is, “Will vitamin D supplements prevent me from developing dementia or Alzheimer’s disease?” This is an area where scientists are a bit more guarded with their optimism. “"We're relatively cautious in how we say this," Joshua Miller, chairman of the department of nutrition in the school of environmental and biological sciences at Rutgers University, said, in an NPR article on the topic. Dr. Knopman adds that “vitamin D is vital to bone metabolism, calcium absorption and other metabolic processes in the body,” however “its role in brain function, cognition and the aging process is still unclear.” So while numerous studies have pointed to the fact that vitamin D plays a role in many non-skeletal conditions, the jury is out when it comes to recommendations.
Sources of Vitamin D
A healthy diet means that most nutrients should come directly from food rather than dietary supplements such as vitamin pills. However, unlike most other essential nutrients vitamin D occurs naturally in very few foods and even then in small quantities. According to the National Institute of Health’s Office of Dietary Supplements, among the best sources are fatty fish such as salmon, tuna and mackerel. Other foods that provide small amounts of vitamin D include beef liver, cheese, egg yolks and mushrooms. Additionally, nearly all milk and many breakfast cereals are fortified with vitamin D, but a substantial portion of this necessary nutrient is synthesized by the body when exposed to direct sunlight.
Skin exposed to sunshine through a window will not synthesize vitamin D. Furthermore, cloudy weather, shade and even skin with a darker complexion can thwart the ability to create the vitamin. Those living at higher latitudes may not be able to synthesize any vitamin D during winter months. That being said, when seeking sunlight, care must be taken to limit exposure due to the risk of skin cancer.
Our modern lifestyle, which frequently includes precious little time outdoors, in combination with the many factors that limit vitamin D synthesis, may indicate a need for dietary supplements. Given that one of the critical benefits to older adults is that, when taken in conjunction with calcium, vitamin D can help ward off conditions like osteoporosis. To the laymen it may seem like a no-brainer to add supplements to one’s diet, but those considering such a change should always discuss this with their physician, to best determine how to improve their health.