Written by Susan Sweeny Johnson, PhD, Biochem. In 80 adults with an average age of 75, half had mild brain size decrease (Alzheimer’s disease) and half were normal. Those with low vitamin D levels performed significantly lower on 2 out of the 4 tests given.
Vitamin D deficiency is present in 25-58% of adults over 60. (1) This is largely due to a decreased ability to make vitamin D in the skin and to use it in the body. (2) Although the correlation of vitamin D with bone density is well established, more recent attention has been paid to the connection between vitamin D and brain function.
Early studies found no correlation of blood concentrations of the vitamin D metabolite, 1,25-dihydroxyvitamin D, with mood disorders, specifically Seasonal Affective Disorder (SAD). (3) SAD is a documented syndrome where people tend to get depressed in the winter due to less sunlight exposure. Later studies, however, have shown that lower levels of 25-hydroxyvitamin D, a more stable metabolite, do correlate with SAD. (4) SAD responds better to Vitamin D supplementation than to sunlight exposure in some studies. (5)
Interestingly, other studies have shown a correlation between higher blood vitamin D levels and better muscle control and fewer falls in the elderly. (6)
In a recent study, 80 adults with an average age of 75 years were selected to participate. Half of the participants had very mild Alzheimer’s symptoms where brain function was only mildly decreased and half had normal brain function. Subjects were divided into three subgroups based on vitamin D level as defined by previously reported data: vitamin D-sufficient (serum level of 25-hydroxyvitamin D of greater than or equal to 20 ng/mL), vitamin D-insufficient (serum 25-hydroxyvitamin D of 10–19.9 ng/mL), and vitamin D-deficient (serum 25-hydroxyvitamin D of less than 10 ng/mL).
All participants were tested using a battery of brain function tests, a mood disorder test, and a muscle control and coordination test. The blood concentration of vitamin D as 25-hydroxyvitamin D was determined only once for each participant.
The results indicate a significant relationship between insufficient vitamin D blood concentrations and mood disorders in elderly people. The score on the mood test correlated with the vitamin D concentration group in a statistically significant manner. The lower the levels of serum 25-hydroxyvitamin D, the lower the scores on the mood test.
Study participants with lower vitamin D levels also performed significantly lower on two of four brain function tests. No correlation of vitamin D levels with muscle control was seen in this study.
Vitamin D supplementation in elderly people may be beneficial in enhancing mood and maintaining brain function. However further, larger studies should be done to more carefully measure blood vitamin D levels over a longer period of time.
Source: Wilkins, Consuelo H., Yvette I. Sheline, Catherine M. Roe, Stanley J. Birge, and John C. Morris. “Vitamin D deficiency is associated with low mood and worse cognitive performance in older adults.” The American Journal of Geriatric Psychiatry 14, no. 12 (2006): 1032-1040.
© 2006 American Association for Geriatric Psychiatry.
Posted December 6, 2008.
References:
- Gloth FM, Gundberg CM, Hollis BW, et al: Vitamin D deficiency in homebound elderly persons. JAMA 1995; 274:1683–1686.
- Parfitt AM, Chir B, Gallagher JC, et al: Vitamin D and bone health in the elderly. Am J Clin Nutr 1982; 36:1014–1031.
- Oren DA, Schulkin J, Rosenthal NE:1,25 (OH)2 vitamin D3 levels in seasonal affective disorder: effects of light. Psychopharmacology 1994;116:515–516.
- Kenny AM, Biskup B, Robbins B, et al: Effects of vitamin D supplementation on strength, physical function, and health perception in older, community-dwelling men. J Am Geriatr Soc 2003; 51:1762–1767.
- Gloth FM 3rd, Alam W, Hollis B: Vitamin D vs broad spectrum phototherapy in the treatment of seasonal affective disorder. J Nutr Health Aging 1999; 3:5–7.
- Bischoff HA, Staehelin HB, Dick W, et al: Effects of vitamin D and calcium supplementation on falls: a randomized controlled trial. J Bone Miner Res 2003; 18:343–351.
