|Blogs||Articles||Organizations||Biography||Jack's Book||Contact Information||Links|
Navigation: SOS Sisson > Traumatic Injury Blog
Jack Sisson's TBI Blog
A hug is duct tape for the soul.
Saturday, December 08, 2012
Vitamin D, calcium disappoint in dementia study
From the Chicago Tribune:
Vitamin D and calcium supplements taken together in low doses offered no protection against dementia in a large U.S. study of older women, but scientists are still holding out hope for vitamin D alone.
Past research has suggested that vitamin D might protect against memory loss and overall functional decline in the aging brain, but more than 2,000 women in the study who took 400 international units of vitamin D and 1,000 mg of calcium daily for an average of eight years developed cognitive impairments at the same rates as a comparison group on placebo pills.
But the study's authors, whose report appeared in the Journal of the American Geriatrics Society, said that during the many years of the study researchers gained a better understanding of how calcium and vitamin D might have conflicting effects, so the combination of the two might explain the disappointing results.
"I think the definitive study will just look at the effects of vitamin D," said lead author Rebecca Rossom, from HealthPartners Institute for Education and Research, a nonprofit arm of a health maintenance organization based in Minnesota.
But she added that the current study is still important because it "gets closer to how women take vitamin D now" to build bone density.
Rossom and her colleagues analyzed data on 4,100 women who were simultaneously enrolled in two trials, including the Women's Health Initiative (WHI) Calcium and Vitamin D trial that ended in 2005, and a WHI memory study.
All of the women, who averaged 71 years old at the outset of the studies, were also free of cognitive problems to start.
Half of the women were assigned to take the supplements, and the rest were given identical-looking dummy pills.
Ultimately, about 100 women, or five percent, in each group developed mild cognitive impairment - a term that can include everything from memory trouble to the serious dementia found in Alzheimer's disease.
The researchers noted that since the study ended, guidelines on vitamin and mineral intakes have changed, Currently the U.S. Institute of Medicine suggests getting 600 IUs per day of vitamin D for men and women up to age 70, and 800 IUs for older people. Suggested calcium ranges from 700 mg to 1,300 mg per day, based on age, with an upper limit of 3,000 mg.
In both cases, intake recommendations cover both food and supplement sources. So, the authors say, their findings are specific only to the assigned amounts of vitamin D and calcium taken by women in the study - which are relatively low by today's standards.
"The sum of information does show conflicting evidence," said Katherine Tucker of Northeastern University, who was not involved in the study.
"Some recent studies suggest that too much calcium could have negative effects. The preponderance of evidence shows that vitamin D is protective, but some studies have shown no effect," she told Reuters Health.
Rossom's team acknowledges their study's limitations. In addition to the doses of supplements, the results are strictly limited to women, who were mostly white. Also, the study participants were relatively young.
LinksTBI Film Reviews
TBI Book Reviews
Traumatic Brain Injury Law Blog
SoapBlox/Chicago: Protecting Our Troops
Head Injury Survival Journal
Losing the Physical Self
Tower of Hanoi: Instructions for this popular puzzle can be viewed simply by clicking the Instructions button on that page.
May 2005 June 2005 July 2005 August 2005 September 2005 October 2005 November 2005 August 2006 September 2006 October 2006 December 2006 January 2007 February 2007 March 2007 April 2007 May 2007 June 2007 July 2007 August 2007 September 2007 October 2007 November 2007 December 2007 January 2008 February 2008 March 2008 January 2009 March 2009 April 2009 December 2009 April 2010 May 2010 June 2010 July 2010 August 2010 September 2010 October 2010 November 2010 January 2011 February 2011 March 2011 April 2011 May 2011 June 2011 July 2011 August 2011 September 2011 October 2011 November 2011 December 2011 January 2012 February 2012 March 2012 April 2012 May 2012 June 2012 October 2012 November 2012 December 2012 January 2013 February 2013 March 2013 April 2013 May 2013 June 2013 October 2013