Vitamin D Deficiency and Cognitive Decline

Dr. David J. Llewellyn and colleagues from all over the world recently conducted the first large longitudinal six-year study on vitamin D and dementia. They studied 858 older adults, seeing if low 25(OH)D levels at baseline predicted the onset or worsening of dementia.

They found that those who were severely deficient (less than10 ng/ml) were 60 percent more likely over the six years to develop dementia compared to those with the highest vitamin D levels. Furthermore, at baseline, 16 patients with levels less than 10 ng/ml were demented compared to only one with levels above 30 ng/ml. Not enough patients had natural levels (50 ng/ml) to see how protective they were.

These results may be understatements as the usual overcorrect ions occurred. For example, obesity, smoking, sex, age and impaired mobility are associated with both dementia and vitamin D deficiency, correcting for them will partially mask the vitamin D contribution and lower the positive findings of the study. In spite of this, the authors stated, "this is the first prospective study to show that low levels of 25(OH)D are associated with elevated risk of cognitive decline."

As we age, most of us fear losing our minds. Dementia, originally meaning madness, is common in the older population; it is a serious loss od cognitive ability in a previously normal person, beyond what is from normal aging. Dementia is usually progressive, resulting in long-term mental decline and eventual severe loss of brain function.

Although dementia is far more common in the geriatric population, it can occur before the age of 65, in which case it is termed "early onset dementia." A recent survey reveled that dementia is the second leading health concern after cancer. My mother, a math teacher, died of dementia and , for the last 10 years of her life, had no idea who I was.

As for vitamin D's beneficial role, the mechanism of action may be simple. At least one study has shown that activated vitamin D helps remove b-amyloid in mammalian brains, the maker cause of dementia.

If this is true, it may mean that vitamin D not only has a preventative effect in dementia, nut also a possible treatment effect, if the brain is not permanently damaged. In such patients, I suggest high normal vitamin D levels, around 80 ng/ml, because of the importance of what is at stake, but don't expect miracles. Again, and I can't state this enough, remember all four co-factors: magnesium, vitamin K, zinc and boron - especially magnesium, usually 500 mg of magnesium citrate daily for adults.

Smart Tan Magazine- Dr. John Cannell- Dr. Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr Cannell holds an M.D. and has served the medical field as a general practitioner, itinerant emergency physician, and psychiatrist.