High calcium and vitamin D intake linked to brain lesions; Researchers blame excess calcium and exonerate vitamin D, which only aids calcium uptake
by Craig Weatherby
Earlier this year, a research review linked higher blood levels of vitamin D to reduced risk of Alzheimer's disease and other forms of dementia.
In their paper, renowned UCLA scientist Bruce Ames, Ph.D., and colleague Joyce McCann, Ph.D., noted the wide distribution of vitamin D receptors throughout the brain.
They also emphasized that vitamin D appears to affect brain proteins responsible for learning and memory, motor control, and behavior.
(See “Vitamin D Shows Brain, Cancer, Colon and Artery Benefits.”)
And the results of a recent study from Holland appear to underscore the importance of vitamin D to brain health.
Dutch study links higher mental test scores to higher vitamin D levels
Earlier this year, Dutch researchers conducted a population study in 225 older outpatients diagnosed with “probable Alzheimer's disease.”
The scientists compared participants' blood levels of vitamin D to their scores on a standard test for dementia (Mini-Mental State Examination, or MMSE).
In addition to vitamin D levels, the researchers also analyzed the participants' blood levels of vitamins B1, B6, and B12, higher levels of which have been linked to reduced risk of dementia in some—but not all—studies.
The results showed that the volunteers with adequate vitamin D levels earned significantly higher scores on the mental status exam, compared to participants with low vitamin D levels (Oudshoorn C et al. 2008).
The study found no association between B-vitamin levels and test scores.
As the authors wrote, “These data support the idea that a relationship exists between vitamin D status and [improved] cognition in patients with probable Alzheimer's disease. Further prospective studies are needed to specify the contribution of vitamin D status to the onset and course of cognitive decline and AD” (Oudshoorn C et al. 2008).
Excess calcium linked to brain damage
Back in April of 2007, scientists from Duke University and the University of North Carolina presented the disturbing results of MRI brain scans of elderly volunteers suffering from depression.
The study involved 232 men and women (79 men, 153 women) between the ages of 60 and 86, almost half of whom had been diagnosed with depression (Payne ME et al. 2007).
The scans showed that those who reported consuming higher levels of calcium and vitamin D (from foods and supplements) had more brain lesions than those who said they consumed less calcium and vitamin D.
Brain lesions are linked to increased risk of cognitive impairment, dementia, depression, and stroke.
What jumped out at us was that higher vitamin D intake had a statistically significant association with having a greater volume of brain lesions.
But before you worry about taking “too much” vitamin D, taking ample amounts of the “sunshine-and-seafood” vitamin doesn't appear to be the main cause of artery calcification, as the researchers noted.
In fact, as Dr. Ames reported, prior studies show just the opposite: having higher vitamin D levels in your blood appears to reduce the risk of dementia (Przybelski RJ, Binkley NC 2007).
What's to blame for damage to brains? Vitamin D or excess calcium?
It appears much more likely that the brain-damaged volunteers' high calcium consumption was the problem, not their vitamin D intake, which was merely adequate.
When too much calcium is taken up into blood vessel walls, the mineral becomes incorporated into hard deposits that reduce the elasticity and diameter of blood vessels.
If blood vessels in the brain are affected, damage could lead to brain lesions.
Vitamin D helps regulate calcium retention in tissues, so higher vitamin D intakes may appear to facilitate arterial calcification, when calcium intake is as high as recommended by misguided U.S. health authorities.
It seems likely, however, that the problem isn't vitamin D per se, but an excess of dietary calcium. In fact, these results suggest that the advice to load up on calcium (“got milk?”) to prevent osteoporosis is misguided.
It's long been known that people in Asian countries with much lower calcium intakes than are typical among dairy-loving Americans have much lower rates of osteoporosis.
Rather than calcium shortages, the preponderance of evidence points to other factors as the villains in osteoporosis:
- Sedentary lifestyles lacking in weight-bearing work or exercise.
- Chronic inflammation. (This is a diet-related factor underlying arterial calcification as well as other key aspects of cardiovascular disease.)
- Lack of omega-3s, magnesium, and vitamin K.
As Martha Payne, M.D., lead author of the Carolina-based brain-scan study, said in a press release, “…the study provides support to the growing number of researchers who are concerned about the effects of too much calcium, particularly among older adults...” (Payne ME et al. 2007).
In other words, get plenty of vitamin D (1,000 to 2,000 IU per day) and if you're an adult over 18, it probably doesn't make sense to take more than about 600 mg of calcium per day, even though the U.S. RDA is a whopping 1,000 mg (age 19 to 50) to 1,200 mg (age 51 or more) per day.
The U.S. government's own calcium fact sheet reveals the real osteoporosis problem: “When calcium intake is low or calcium is poorly absorbed, bone breakdown occurs...” (ODS 2008).
The key phrase here is “…or calcium is poorly absorbed…”
If you don't get enough vitamin D, magnesium, vitamin K, omega-3s, and exercise, all the calcium in the world won't help. It will just end up in your arteries, or form painful kidney stones.
- Federation of American Societies for Experimental Biology (FASEB). Higher calcium and vitamin D intakes positively associated with brain lesions in older men and women. May 1, 2007. Accessed online August 14, 2008 at http://www.eurekalert.org/pub_releases/2007-05/foas-hca042007.php.
- Office of Dietary Supplements, National Institutes of Health (ODS). Dietary Supplement Fact Sheet: Calcium. Accessed online August 14, 2008 at http://ods.od.nih.gov/factsheets/calcium.asp
- Oudshoorn C, Mattace-Raso FU, van der Velde N, Colin EM, van der Cammen TJ. Higher serum vitamin D3 levels are associated with better cognitive test performance in patients with Alzheimer's disease. Dement Geriatr Cogn Disord. 2008;25(6):539-43. Epub 2008 May 26.
- Payne ME, Anderson J, Steffens DC. Calcium and vitamin D intakes are positively associated with brain lesions in depressed and non-depressed elders. FASEB J. 2007 21:837.20
- Przybelski RJ, Binkley NC. Is vitamin D important for preserving cognition? A positive correlation of serum 25-hydroxyvitamin D concentration with cognitive function. Arch Biochem Biophys. 2007 Apr 15;460(2):202-5. Epub 2007 Jan 8.
- Wilkins CH, Sheline YI, Roe CM, Birge SJ, Morris JC. Vitamin D deficiency is associated with low mood and worse cognitive performance in older adults. Am J Geriatr Psychiatry. 2006 Dec;14(12):1032-40.