PLYMOUTH medical researchers have discovered a link between lack of the 'sunshine vitamin' and the onset of dementia.\n\nTeams from the city's Peninsula Medical School and the universities of Cambridge and Michigan have for the first time found a relationship between lower Vitamin D levels and cognitive impairment in older people.\n\nThe results of their large-scale study are to be published in the Journal of Geriatric Psychology and Neurology.
A randomized controlled trial of vitamin D3 supplementation for the prevention of symptomatic upper respiratory tract infections.
Li-Ng M, Aloia JF, Pollack S, Cunha BA, Mikhail M, Yeh J, Berbari N.
Epidemiol Infect. 2009 Mar 19:1-9. [Epub ahead of print]
PMID: 19296870
Vitamin D in preventive medicine: are we ignoring the evidence?
Zittermann A.
Br J Nutr. 2003 May;89(5):552-72. Review.
PMID: 12720576
Vitamin D is metabolised by a hepatic 25-hydroxylase into 25-hydroxyvitamin D (25(OH)D) and by a renal 1alpha-hydroxylase into the vitamin D hormone calcitriol. Calcitriol receptors are present in more than thirty different tissues. Apart from the kidney, several tissues also possess the enzyme 1alpha-hydroxylase, which is able to use circulating 25(OH)D as a substrate. Serum levels of 25(OH)D are the best indicator to assess vitamin D deficiency, insufficiency, hypovitaminosis, adequacy, and toxicity. European children and young adults often have circulating 25(OH)D levels in the insufficiency range during wintertime. Elderly subjects have mean 25(OH)D levels in the insufficiency range throughout the year. In institutionalized subjects 25(OH)D levels are often in the deficiency range. There is now general agreement that a low vitamin D status is involved in the pathogenesis of osteoporosis. Moreover, vitamin D insufficiency can lead to a disturbed muscle function. Epidemiological data also indicate a low vitamin D status in tuberculosis, rheumatoid arthritis, multiple sclerosis, inflammatory bowel diseases, hypertension, and specific types of cancer. Some intervention trials have demonstrated that supplementation with vitamin D or its metabolites is able: (i) to reduce blood pressure in hypertensive patients; (ii) to improve blood glucose levels in diabetics; (iii) to improve symptoms of rheumatoid arthritis and multiple sclerosis. The oral dose necessary to achieve adequate serum 25(OH)D levels is probably much higher than the current recommendations of 5-15 microg/d.
A seasonal variation of calcitropic hormones, bone turnover and bone mineral density in early and mid-puberty girls - a cross-sectional study.
Viljakainen HT, Palssa A, Kärkkäinen M, Jakobsen J, Cashman KD, Mølgaard C, Lamberg-Allardt C.
Br J Nutr. 2006 Jul;96(1):124-30.
PMID: 16870000
Seasonal variation in S-25-OHD and bone remodelling markers accompanied by negative correlation between S-25-OHD and S-iPTH was seen in this cross-sectional study of adolescent girls. In addition, the seasonal rhythm contributed 7.0-7.6 % difference in the BMD of lumbar vertebrae and left femur in early puberty girls. This variation should be avoided since it could hamper peak bone mass attainment.
Vitamin D and disease prevention with special reference to cardiovascular disease.
Zittermann A.
Prog Biophys Mol Biol. 2006 Sep;92(1):39-48. Epub 2006 Feb 28. Review.
PMID: 1660034
Serum 25-Hydroxyvitamin D Concentration and Cognitive Impairment.\nLlewellyn DJ, Langa K, Lang I.\nJ Geriatr Psychiatry Neurol. 2009 Feb 4. [Epub ahead of print]\nPMID: 19073839 \ndoi:10.1177/0891988708327888\n
Geographical differences in vitamin D status, with particular reference to European countries
Lars Ovesen*, Rikke Andersen and Jette Jakobsen
Institute of Food Safety and Nutrition, The Danish Veterinary and Food Administration, 30A Sydmarken, 2860 S
Hypovitaminosis D in an Italian population of healthy subjects and hospitalized patients.
Romagnoli E, Caravella P, Scarnecchia L, Martinez P, Minisola S.
Br J Nutr. 1999 Feb;81(2):133-7.
PMID: 10450331
The results of the present study emphasize the importance of 25-hydroxyvitamin D measurement, and the need to increase vitamin D intake in Italy; foodstuff fortification and supplement use must be considered in order to prevent negative effects of vitamin D deficiency on skeletal integrity.
All hospitalized patients, both in summer and in winter,
are characterized by the highest prevalence of hypovitaminosis
D, especially the older patients. Medical
inpatients may be at risk for vitamin D deficiency,
Vitamin D supplementation reduces insulin resistance in South Asian women living in New Zealand who are insulin resistant and vitamin D deficient - a randomised, placebo-controlled trial.
von Hurst PR, Stonehouse W, Coad J.
Br J Nutr. 2009 Sep 28:1-7. [Epub ahead of print]
PMID: 19781131
In conclusion, improving vitamin D status in insulin resistant women resulted in improved IR and sensitivity, but no change in insulin secretion. Optimal vitamin D concentrations for reducing IR were shown to be 80-119 nmol/l, providing further evidence for an increase in the recommended adequate levels. Registered Trial No. ACTRN12607000642482.
A randomised comparison of increase in serum 25-hydroxyvitamin D concentration after 4 weeks of daily oral intake of 10 microg cholecalciferol from multivitamin tablets or fish oil capsules in healthy young adults.
Holvik K, Madar AA, Meyer HE, Lofthus CM, Stene LC.
Br J Nutr. 2007 Sep;98(3):620-5. Epub 2007 Apr 24.
PMID: 17456248
We conclude that fish oil capsules and multivitamin tablets containing 10 microg cholecalciferol administered over a 4-week period produced a similar mean increase in s-25(OH)D concentration.