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Author Topic: How Would It Be To Live Without Light ?  (Read 16770 times)

Offline iko

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How Would It Be To Live Without Light ?
« Reply #25 on: 10/11/2008 17:57:18 »
It seems to me that you would need to check that the diets of the two groups (suffering from dementia and not doing) were similar before you could make any progress attributing cause and effect here.
The association between Vit D and dementia is, no doubt, just what that study says, but is it because people with low Vit. D levels become demented or is it that demented people don't get enough vit D from their diet or, as RD suggests, from sunlight.

So which come first, the chicken or the egg?  ???

Apparently we get most of our vit.D from the sunlight, apart from some North-Europe country where they take cod liver oil...
As you probably know, Canada is leading in the "more D" campaign.
Studies are on progress, at least in mild forms of depression, like the so called "winter depression".
Here there is a rare example of one of the first randomized clinical trial with cheap vitamin D versus placebo:

Randomized comparison of the effects of the vitamin D3 adequate intake versus 100 mcg (4000 IU) per day on biochemical responses and the wellbeing of patients.

Vieth R, Kimball S, Hu A, Walfish PG.
Department of Laboratory Medicine and Pathology, University of Toronto, Canada.

BACKGROUND: For adults, vitamin D intake of 100 mcg (4000 IU)/day is physiologic and safe. The adequate intake (AI) for older adults is 15 mcg (600 IU)/day, but there has been no report focusing on use of this dose.
METHODS: We compared effects of these doses on biochemical responses and sense of wellbeing in a blinded, randomized trial. In Study 1, 64 outpatients (recruited if summer 2001 25(OH)D <61 nmol/L) were given 15 or 100 mcg/day vitamin D in December 2001. Biochemical responses were followed at subsequent visits that were part of clinical care; 37 patients completed a wellbeing questionnaire in December 2001 and February 2002. Subjects for Study 2 were recruited if their 25(OH)D was <51 nmol/L in summer 2001. 66 outpatients were given vitamin D; 51 completed a wellbeing questionnaire in both December 2002 and February 2003. RESULTS: In Study 1, basal summer 25-hydroxyvitamin D [25(OH)D] averaged 48 +/- 9 (SD) nmol/L. Supplementation for more than 6 months produced mean 25(OH)D levels of 79 +/- 30 nmol/L for the 15 mcg/day group, and 112 +/- 41 nmol/L for the 100 mcg/day group. Both doses lowered plasma parathyroid hormone with no effect on plasma calcium. Between December and February, wellbeing score improved more for the 100-mcg/day group than for the lower-dosed group (1-tail Mann-Whitney p = 0.036). In Study 2, 25(OH)D averaged 39 +/- 9 nmol/L, and winter wellbeing scores improved with both doses of vitamin D (two-tail p < 0.001).

CONCLUSION: The highest AI for vitamin D brought summertime 25(OH)D to >40 nmol/L, lowered PTH, and its use was associated with improved wellbeing. The 100 mcg/day dose produced greater responses. Since it was ethically necessary to provide a meaningful dose of vitamin D to these insufficient patients, we cannot rule out a placebo wellbeing response, particularly for those on the lower dose. This work confirms the safety and efficacy of both 15 and 100 mcg/day vitamin D3 in patients who needed additional vitamin D.

Nutr J. 2004 Jul 19;3:8.

« Last Edit: 10/11/2008 18:09:52 by iko »

The Naked Scientists Forum

How Would It Be To Live Without Light ?
« Reply #25 on: 10/11/2008 17:57:18 »


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