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Matti Narkia

Vitamin D in preventive medicine: are we ignoring the evidence? - 0 views

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    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.
Matti Narkia

Common genetic variants of the vitamin D binding protein (DBP) predict differences in r... - 0 views

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    BACKGROUND: To determine the effect of vitamin D binding protein (DBP) genotypes on 25-hydroxyvitamin D [25(OH)D] changes with vitamin D supplements, we studied 98 adults receiving 600 or 4000 IU/d vitamin D(3) for one year. METHODS: The DBP functional variant, T436K, was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Mean 25(OH)D increases were 97% for TT (n=48), 151% for TK (n=31) and 307% (n=6) for KK genotypes (p=.004). CONCLUSIONS: As with baseline 25(OH)D, T436K genotype predicts 25(OH)D changes after long-term vitamin D supplementation. Common genetic variants of the vitamin D binding protein (DBP) predict differences in response of serum 25-hydroxyvitamin D [25(OH)D] to vitamin D supplementation. Fu L, Yun F, Oczak M, Wong BY, Vieth R, Cole DE. Clin Biochem. 2009 Jul;42(10-11):1174-7. Epub 2009 Mar 18. PMID: 19302999
Matti Narkia

Use of vitamin D in clinical practice. - Altern Med Rev. 2008 Mar - 0 views

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    Use of vitamin D in clinical practice. Cannell JJ, Hollis BW. Altern Med Rev. 2008 Mar;13(1):6-20. PMID: 18377099 The recent discovery--from a meta-analysis of 18 randomized controlled trials--that supplemental cholecalciferol (vitamin D) significantly reduces all-cause mortality emphasizes the medical, ethical, and legal implications of promptly diagnosing and adequately treating vitamin D deficiency. Not only are such deficiencies common, and probably the rule, vitamin D deficiency is implicated in most of the diseases of civilization. Vitamin D's final metabolic product is a potent, pleiotropic, repair and maintenance, seco-steroid hormone that targets more than 200 human genes in a wide variety of tissues, meaning it has as many mechanisms of action as genes it targets. One of the most important genes vitamin D up-regulates is for cathelicidin, a naturally occurring broad-spectrum antibiotic. Natural vitamin D levels, those found in humans living in a sun-rich environment, are between 40-70 ng per ml, levels obtained by few modern humans. Assessing serum 25-hydroxy-vitamin D (25(OH)D) is the only way to make the diagnosis and to assure treatment is adequate and safe. Three treatment modalities exist for vitamin D deficiency: sunlight, artificial ultraviolet B (UVB) radiation, and vitamin D3 supplementation. Treatment of vitamin D deficiency in otherwise healthy patients with 2,000-7,000 IU vitamin D per day should be sufficient to maintain year-round 25(OH)D levels between 40-70 ng per mL. In those with serious illnesses associated with vitamin D deficiency, such as cancer, heart disease, multiple sclerosis, diabetes, autism, and a host of other illnesses, doses should be sufficient to maintain year-round 25(OH)D levels between 55 -70 ng per mL. Vitamin D-deficient patients with serious illness should not only be supplemented more aggressively than the well, they should have more frequent monitoring of serum 25(OH)D and serum calcium. Vitamin D should always be
Matti Narkia

Circulating Vitamin D3 and 25-hydroxyvitamin D in Humans: An Important Tool to Define A... - 0 views

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    Circulating vitamin D3 and 25-hydroxyvitamin D in humans: An important tool to define adequate nutritional vitamin D status. Hollis BW, Wagner CL, Drezner MK, Binkley NC. J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):631-4. Epub 2007 Jan 10. PMID: 17218096 In the present study, we sought to investigate what circulating 25(OH)D levels would result in populations exhibiting no substrate limitations to the vitamin D-25-hydroxylase. To perform this, we chose two distinct populations. The first were individuals from a year-found sunny environment who spent a good deal of time outdoors. The second were a group of lactating women receiving a substantial daily oral dose of vitamin D3. Surprisingly, a study such as this previously had not been undertaken. There are several reasons for this. First, finding a group of sun-exposed individuals is not an easy task; in fact, we had to go to Hawaii to find them. Secondly, very few studies have been performed where subjects actually received adequate vitamin D3 supplementation to make them replete. Finally, it is very difficult and costly to measure circulating vitamin D3 and relate it to circulating 25(OH)D. The results of our study are far-reaching. This study also demonstrates that individuals can be vitamin D deficient with significant sun exposure if the skin area exposed is limited as was suggested several years ago (19). Finally, whether one receives their vitamin D3 orally or through UV exposure, the vitamin D-25-hydroxylase appears to handle it in an equivalent fashion with respect to maintaining circulating 25(OH)D levels. Thus, we believe that the relationship between circulating vitamin D and 25(OH)D may define adequate nutritional vitamin D status.
Matti Narkia

Severe vitamin D deficiency in Swiss hip fracture patients. - [Bone. 2008] - PubMed Result - 1 views

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    Severe vitamin D deficiency in Swiss hip fracture patients. Bischoff-Ferrari HA, Can U, Staehelin HB, Platz A, Henschkowski J, Michel BA, Dawson-Hughes B, Theiler R. Bone. 2008 Mar;42(3):597-602. Epub 2007 Nov 28. PMID: 18180211 BACKGROUND: Most clinical guidelines for the prevention of hip fractures recommend 800 IU vitamin D per day. This dose shifted serum 25-hydroxyvitamin D levels (25(OH)D) in previous studies to between 60 and 100 nmol/l. AIM: To measure 25(OH)D levels and prevalence of vitamin D supplementation in individuals age 65+ with acute hip fracture. METHODS: 222 consecutive hip fracture patients were investigated over a 12 month period. Mean age of patients was 86 years and 77% were women. RESULTS: Mean serum 25(OH)D levels were low among hip fracture patients admitted from home (34.6 nmol/l), from assisted living (27.7 nmol/l), and from nursing homes (24 nmol/l). Severe vitamin D deficiency below 30 nmol/l was present in 60%, 80% were below 50 nmol/l, and less than 4% reached desirable levels of at least 75 nmol/l. Consistently, only 10% of hip fracture patients had any vitamin D supplementation on admission to acute care with significantly higher 25(OH)D levels among individuals supplemented with 800-880 IU/day (63.5 nmol/l). Controlling for age and gender, vitamin D supplementation, type of dwelling, and season were independently and significantly associated with 25(OH)D levels. CONCLUSION: These data provide evidence that current guidelines for the prevention of hip fractures need further effort to be translated into clinical practice.
Matti Narkia

D-vitamiini ravintolisänä. Hyöty- ja riskiarvio | Tohtori Tolonen - 1 views

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    "D-vitamiini on nyt valtavan suosittu ravintolisä. Tähän asti tämän vitamiinin yliannostelun vaaroilla on peloteltu, mutta nyttemmin on käynyt ilmeiseksi, että pelottelu on ollut turhaa ja suorastaan turmiollista kansanterveydelle ja -taloudelle. Maailman johtavat sveitsiläiset ja amerikkalaiset D-vitamiinitutkijat esittävät arvionsa D-vitamiinin hyödyistä ja riskeistä luukadon ehkäisyssä. Voimassa olevat D-vitamiinin päivittäiset saantisuositukset - jotka vaihtelevat eri maissa 5 ja 15 mikrogramman (µg) välillä - voivat olla liian pienet tämän vitamiinin monipuolisten vaikutusten kannalta monien eri tautien ehkäisyssä, toteavat tutkijat kirjoituksensa alussa. He arvioivat suosituksia suurempien D-vitamiiniannosten hyötyjä ja punnitsivat mahdollisia riskejä erityisesti seerumin D-vitamiinin pitoisuuden (25-OHD, S-D-25) valossa. Arviointi perustuu satunnaistettuihin kaksoissokkokokeisiin, joista 8 käsitteli ikääntyvien ihmisten kaatumisia (N=2426) ja 12 luunmurtumia (N=42279). Tulokset osoittivat, että mitä suurempi S-D-25 oli, sitä vähemmän oli kaatumisia ja murtumia. Tosiin sanoen, suuri S-D-25 ehkäisee ikäihmisillä sekä kaatumisia että luunmurtumia. Ihanteellinen S-D-25 näyttää olevan 75-110 nmol/l, johon on mahdollista päästä nauttimalla ruoan lisänä D-vitamiinia 17,5-25 µg, päättelivät tutkijat edellä mainittujen poikkileikkaustutkimusten valossa. "
Matti Narkia

Vitamin D receptor (VDR) gene polymorphisms and haplotypes, interactions with plasma 25... - 0 views

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    Vitamin D receptor (VDR) gene polymorphisms and haplotypes, interactions with plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and prostate cancer risk. Mikhak B, Hunter DJ, Spiegelman D, Platz EA, Hollis BW, Giovannucci E. Prostate. 2007 Jun 15;67(9):911-23. PMID: 17440943 DOI: 10.1002/pros.20570 RESULTS No association was found between these SNPs or their associated haplotypes and all PC subtypes except that haplotype 2 (A-f-b) with Cdx2 A, Fok1 f, and Bsm1 b alleles and haplotype 3 (A-F-B) with Cdx2 A, Fok1 F and Bsm1 B alleles compared to the most common haplotype (A-F-b), were associated with reduced risk of aggressive PC (high stage or Gleason sum 7; P = 0.02), both with two alleles suspected of being low risk. Carriers of the variant Cdx2 A allele who were deficient in plasma 25-hydroxyvitamin D (15 ng/ml) compared to non-carriers with normal 25-hydroxyvitamin D, had a lower risk of total and poorly differentiated PCs (Gleason sum 7) (P for interaction = 0.02 and 0.04, respectively). Plasma 1,25-dihydroxyvitamin D deficiency (26 pg/ml) was associated with a threefold risk of poorly differentiated PC (P for interaction = 0.01) when comparing carriers of the Cdx2 A allele to non-carriers with normal 1,25-dihydroxyvitamin D. CONCLUSION In this population of men, none of the VDR polymorphisms studied was associated with susceptibility to PC. Carriers of the variant Cdx2 A allele with low plasma 25-hydroxyvitamin D may experience a reduction in risk of total and poorly differentiated prostate cancers compared to non-carriers with adequate 25-hydroxyvitamin D.
Matti Narkia

Improved Cholecalciferol Nutrition in Rats Is Noncalcemic, Suppresses Parathyroid Hormo... - 0 views

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    Improved cholecalciferol nutrition in rats is noncalcemic, suppresses parathyroid hormone and increases responsiveness to 1, 25-dihydroxycholecalciferol. Vieth R, Milojevic S, Peltekova V. J Nutr. 2000 Mar;130(3):578-84. PMID: 10702588 We conclude suppression of 1,25(OH)(2)D and PTH, and higher renal VDR mRNA and 24-hydroxylase did not involve higher free 1,25(OH)(2)D concentration or a first pass effect at the gut. Thus, 25(OH)D or a metabolite other than 1,25(OH)(2)D is a physiological, transcriptionally and biochemically active, noncalcemic vitamin D metabolite. When viewed from a perspective that starts with higher vitamin D nutrition, the results indicate that low vitamin D nutrition may bring about a form of resistance to 1,25(OH)2D. This situation would explain why, in humans, nutritional rickets and osteomalacia are commonly associated with normal or increased levels of 1,25(OH)2D (Chesney et al. 1981Citation , Eastwood et al. 1979Citation , Garabedian et al. 1983Citation ,Rasmussen et al. 1980Citation )-these are not like the low hormone levels associated with any other endocrine-deficiency disorder. A connection between lower vitamin D nutrition and vitamin D resistance helps to explain why the supposedly inactive compound 25(OH)D is more relevant in diagnosing nutritional rickets than is the active hormone 1,25(OH)2D. If the features of improved vitamin D nutrition shown here were demonstrated for any newly synthesized compound, the compound would be classified as a noncalcemic 1,25(OH)2D analogue (Brown et al. 1989Citation , Finch et al. 1999Citation , Goff et al. 1993Citation , Koshizuka et al. 1999Citation ). Thus, we contend that 25(OH)D or a metabolite of it other than 1,25(OH)2D exists as a physiological and biologically-active noncalcemic vitamin D metabolite whose effects require further examination, particularly in relationship to studies involving the synthetic analogs of 1,25(OH)2D.
Matti Narkia

Take or avoid vitamin D supplements? - ImmInst.org Forums - 0 views

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    "Hi! This is Amy Proal. I wrote the article referenced at the start of the thread about vitamin D. Dr. Marshall is not concerned with vitamin D toxicity. Rather his molecular modeling research has clarified the actions of the two vitamin D metabolites 25-D and 1,25-D. The Vitamin D Receptor (VDR) is a fundamental receptor of the body - it controls the expression thousands of genes, as well as the activity of the innate immune system and the antimicrobial peptides. If you think of the VDR as a switch, 25-D (which is a corticosteroid) turns it off (inactivates it) and 1,25-D turn it on (activates it). What is commonly believed among vitamin D researchers is that if people supplement with extra vitamin D it will be converted into 1,25-D and activate the VDR. Unfortunately, Marshall's work revealed that the type of vitamin D derived from supplements and sun remains, for the most part, in it's precursor form 25-D. This means that the extra vitamin D we get from fortified food products and supplements is turning the VDR off, not on. That causes a decrease in immune function and gene transcription."
Matti Narkia

Effectiveness and Safety of Vitamin D in Relation to Bone Health (full text) - 0 views

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    Effectiveness and safety of vitamin D in relation to bone health. Cranney A, Horsley T, O'Donnell S, Weiler H, Puil L, Ooi D, Atkinson S, Ward L, Moher D, Hanley D, Fang M, Yazdi F, Garritty C, Sampson M, Barrowman N, Tsertsvadze A, Mamaladze V. Evid Rep Technol Assess (Full Rep). 2007 Aug;(158):1-235. Review. PMID: 18088161 CONCLUSIONS: The results highlight the need for additional high quality studies in infants, children, premenopausal women, and diverse racial or ethnic groups. There was fair evidence from studies of an association between circulating 25(OH)D concentrations with some bone health outcomes (established rickets, PTH, falls, BMD). However, the evidence for an association was inconsistent for other outcomes (e.g., BMC in infants and fractures in adults). It was difficult to define specific thresholds of circulating 25(OH)D for optimal bone health due to the imprecision of different 25(OH)D assays. Standard reference preparations are needed so that serum 25(OH)D can be accurately and reliably measured, and validated. In most trials, the effects of vitamin D and calcium could not be separated. Vitamin D(3) (>700 IU/day) with calcium supplementation compared to placebo has a small beneficial effect on BMD, and reduces the risk of fractures and falls although benefit may be confined to specific subgroups. Vitamin D intake above current dietary reference intakes was not reported to be associated with an increased risk of adverse events. However, most trials of higher doses of vitamin D were not adequately designed to assess long-term harms.
Matti Narkia

Effectiveness and safety of vitamin D in relation to bone health. - [Evid Rep Technol A... - 0 views

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    Effectiveness and safety of vitamin D in relation to bone health. Cranney A, Horsley T, O'Donnell S, Weiler H, Puil L, Ooi D, Atkinson S, Ward L, Moher D, Hanley D, Fang M, Yazdi F, Garritty C, Sampson M, Barrowman N, Tsertsvadze A, Mamaladze V. Evid Rep Technol Assess (Full Rep). 2007 Aug;(158):1-235. Review. PMID: 18088161 CONCLUSIONS: The results highlight the need for additional high quality studies in infants, children, premenopausal women, and diverse racial or ethnic groups. There was fair evidence from studies of an association between circulating 25(OH)D concentrations with some bone health outcomes (established rickets, PTH, falls, BMD). However, the evidence for an association was inconsistent for other outcomes (e.g., BMC in infants and fractures in adults). It was difficult to define specific thresholds of circulating 25(OH)D for optimal bone health due to the imprecision of different 25(OH)D assays. Standard reference preparations are needed so that serum 25(OH)D can be accurately and reliably measured, and validated. In most trials, the effects of vitamin D and calcium could not be separated. Vitamin D(3) (>700 IU/day) with calcium supplementation compared to placebo has a small beneficial effect on BMD, and reduces the risk of fractures and falls although benefit may be confined to specific subgroups. Vitamin D intake above current dietary reference intakes was not reported to be associated with an increased risk of adverse events. However, most trials of higher doses of vitamin D were not adequately designed to assess long-term harms.
Matti Narkia

Vitamin D Status: Measurement, Interpretation, and Clinical Application - 0 views

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    Vitamin D status: measurement, interpretation, and clinical application. Holick MF. Ann Epidemiol. 2009 Feb;19(2):73-8. Epub 2008 Mar 10. Review. PMID: 18329892 Conclusion The only way to determine whether a person is vitamin D deficient or sufficient is to measure their circulating level of 25(OH)D. There are a variety of assays used to measure 25(OH)D. The radioimmunoassays and competitive protein binding assays for 25(OH)D are useful in detecting vitamin D deficiency and sufficiency. However, these assays are fraught with technical difficulties, especially if they are not run routinely (Fig. 4) (33). Several reference laboratories have now switched to LC-MS ,which measures both 25(OH)D2 and 25(OH)D3 quantitatively. The total 25(OH)D, i.e., 25(OH)D2 plus 25(OH)D3, is what physicians need to be aware of for their patients. A level >30 ng/mL is
Matti Narkia

Manninen Nutraceuticals: D-vitamiinitabletti vs. D-vitamiiniöljykapseli - 0 views

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    "Kuluttajille on eräillä keskustelufoorumeilla yritelty uskotella, että öljypohjaiset D-vitamiinivalmisteet omaavat paremman biologisen hyväksikäytettävyyden kuin D-vitamiinitabletit, mutta tälle väitteelle ei löydy mitään tukea tieteellisestä kirjallisuudesta. Norjalaistutkimuksessa verrattiin D3-vitamiinia sisältävät multivitamiinitabletin ja D3-vitamiinia sisältävän kalaöljykapselin vaikutuksia seerumin (veren) 25-OH-D-vitamiinipitoisuuteen (S-25(OH)D). Koehenkilöt saivat neljän viikon ajan 10 mikrogrammaa D3-vitamiinia joko tableteista tai öljykapseleista. Tablettiryhmässä S-25(OH)D-pitoisuus nousi keskimäärin 35,8 nmol/l ja kapseliryhmässä 32,3 nmol/l. "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", päättelivät tutkijat. Vuotta aiemmin julkaistussa suomalaistutkimuksessa havaittiin, että D3-vitamiini imeytyy erilaisista leivistä samalla tehokkuudella kuin D-vitamiinivalmisteesta. Kanadalaistutkijat raportoivat juuston osalta samanlaisia tuloksia. Vuonna 2003 jenkkitutkijat totesivat, että "fat is not required for vitamin D to be bioavailable." Mainittakoon lopuksi, että D3-vitamiinitabletteihin lisätään yleensä D3-vitamiinivalmistetta, jossa on öljy jo valmiina. Ainesosaluetteloissa lukee lähes säännönmukaisesti "D3-vitamiinivalmiste" ja sen jälkeen suluissa pelkkä aktiiviaine eli "kolekalsiferoli" tai "sisältää mm. kolekalsiferolia ja soijaöljyä" tai jotain vastaavaa. Tämä D3-vitamiinivalmiste on sitten ympäröity täyteaineilla, jotka eivät vaikuta D3-vitamiinin imeytymiseen millään tavalla. Tabletti hajoaa hyvin nopeasti maha-suolikanavassa."
Matti Narkia

Vitamin D and calcium insufficiency-related chronic diseases: molecular and cellular pa... - 0 views

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    Vitamin D and calcium insufficiency-related chronic diseases: molecular and cellular pathophysiology. Peterlik M, Cross HS. Eur J Clin Nutr. 2009 Dec;63(12):1377-86. Epub 2009 Sep 2. PMID: 19724293 doi:10.1038/ejcn.2009.105 A compromised vitamin D status, characterized by low 25-hydroxyvitamin D (25-(OH)D) serum levels, and a nutritional calcium deficit are widely encountered in European and North American countries, independent of age or gender. Both conditions are linked to the pathogenesis of many degenerative, malignant, inflammatory and metabolic diseases. Studies on tissue-specific expression and activity of vitamin D metabolizing enzymes, 25-(OH)D-1alpha-hydroxylase and 25-(OH)D-24-hydroxylase, and of the extracellular calcium-sensing receptor (CaR) have led to the understanding of how, in non-renal tissues and cellular systems, locally produced 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and extracellular Ca2+ act jointly as key regulators of cellular proliferation, differentiation and function. Impairment of cooperative signalling from the 1,25-(OH)2D3-activated vitamin D receptor (VDR) and from the CaR in vitamin D and calcium insufficiency causes cellular dysfunction in many organs and biological systems, and, therefore, increases the risk of diseases, particularly of osteoporosis, colorectal and breast cancer, inflammatory bowel disease, insulin-dependent diabetes mellitus type I, metabolic syndrome, diabetes mellitus type II, hypertension and cardiovascular disease. Understanding the underlying molecular and cellular processes provides a rationale for advocating adequate intake of vitamin D and calcium in all populations, thereby preventing many chronic diseases worldwide.
Matti Narkia

Vitamin D and breast cancer. - Ann Epidemiol. 2009 Jul (full text PDF) - 0 views

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    Vitamin D and breast cancer. Bertone-Johnson ER. Ann Epidemiol. 2009 Jul;19(7):462-7. Epub 2009 Feb 20. Review. PMID: 19230714 Though the relationship between vitamin D and breast cancer remains unclear, a growing body of evidence suggests that vitamin D may modestly reduce risk. A large number of in vitro studies indicate that vitamin D can inhibit cell proliferation and promote apoptosis and cell differentiation in breast tumor tissue. Results from analytic studies of sunlight exposure and dietary intake have been inconsistent but together generally support a modestly protective role of vitamin D, at least in some population subgroups. Studies using blood vitamin D metabolites to assess vitamin D status may be less prone to misclassification than those of diet and sunlight exposure. Overall, the two prospective and four case-control studies of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D tend to support a protective effect in older women. The relationship between common vitamin D receptor polymorphisms and risk remains unclear. Many questions about this relationship clearly remain, including the utility of assessing vitamin D through diet and sunlight exposure, the relationship between plasma metabolites, and the potential modifying effects of age, menopausal status and tumor characteristics. Given that vitamin D status is modifiable, additional prospective studies are necessary to determine if vitamin D may have important potential for breast cancer prevention.
Matti Narkia

Serum 25-hydroxyvitamin D status of the US population: 1988-1994 compared with 2000-200... - 0 views

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    Serum 25-hydroxyvitamin D status of the US population: 1988-1994 compared with 2000-2004. Looker AC, Pfeiffer CM, Lacher DA, Schleicher RL, Picciano MF, Yetley EA. Am J Clin Nutr. 2008 Dec;88(6):1519-27. PMID: 19064511 doi:10.3945/ajcn.2008.26182 Conclusions: Overall, mean serum 25(OH)D was lower in 2000-2004 than 1988-1994. Assay changes unrelated to changes in vitamin D status accounted for much of the difference in most population groups. In an adult subgroup, combined changes in BMI, milk intake, and sun protection appeared to contribute to a real decline in vitamin D status. In summary, age-standardized mean serum 25(OH)D concentrations based on observed values were significantly lower in 2000-2004 than in 1988-1994 in all groups examined. Adjustment for assay changes noticeably reduced the difference between surveys. However, mean serum 25(OH)D concentrations remained significantly lower in males (except Mexican Americans) in NHANES 2000-2004 than in NHANES III, even after adjustment for assay differences. This remaining difference likely represents a real decline in vitamin D status. Changes in BMI, milk intake, and sun protection appeared to contribute to this decline in a subgroup of non-Hispanic white adults. The possibility that trends in overweight, sun protection, and milk intake may continue supports the need to continue monitoring the serum 25(OH)D status of the population
Matti Narkia

Cod liver oil, vitamin A toxicity, frequent respiratory infections, and the vitamin D d... - 0 views

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    Cod liver oil, vitamin A toxicity, frequent respiratory infections, and the vitamin D deficiency epidemic. Cannell JJ, Vieth R, Willett W, Zasloff M, Hathcock JN, White JH, Tanumihardjo SA, Larson-Meyer DE, Bischoff-Ferrari HA, Lamberg-Allardt CJ, Lappe JM, Norman AW, Zittermann A, Whiting SJ, Grant WB, Hollis BW, Giovannucci E. Ann Otol Rhinol Laryngol. 2008 Nov;117(11):864-70. Review. PMID: 19102134 Until we have better information on doses of vitamin D that will reliably provide adequate blood levels of 25(OH)D without toxicity, treatment of vitamin D deficiency in otherwise healthy children should be individualized according to the numerous factors that affect 25(OH)D levels, such as body weight, percent body fat, skin melanin, latitude, season of the year, and sun exposure.2 The doses of sunshine or oral vitamin D3 used in healthy children should be designed to maintain 25(OH)D levels above 50 ng/mL. As a rule, in the absence of significant sun exposure, we believe that most healthy children need about 1,000 IU of vitamin D3 daily per 11 kg (25 lb) of body weight to obtain levels greater than 50 ng/mL. Some will need more, and others less. In our opinion, children with chronic illnesses such as autism, diabetes, and/or frequent infections should be supplemented with higher doses of sunshine or vitamin D3, doses adequate to maintain their 25(OH)D levels in the mid-normal of the reference range (65 ng/mL) - and should be so supplemented year round. Otolaryngologists treating children are in a good position to both diagnose and treat vitamin D deficiency.
Matti Narkia

Vitamin D: a D-Lightful health perspective. - Nutr Rev. 2008 Oct;66(10 Suppl 2):S182-94... - 0 views

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    Vitamin D: a D-Lightful health perspective. Holick MF. Nutr Rev. 2008 Oct;66(10 Suppl 2):S182-94. Review. PMID: 18844847 DOI: 10.1111/j.1753-4887.2008.00104.x Sunlight provides most humans with their vitamin D requirement. Adequate vitamin D(3) by synthesis in the skin or from dietary and supplemental sources is essential for bone health throughout life. Vitamin D deficiency is defined as a 25(OH)D concentration 30 ng/mL (75 nmol/L), and insufficiency as 21-29 ng/mL. Vitamin D deficiency and insufficiency has been linked to a wide variety of chronic diseases including common cancers, autoimmune, cardiovascular, and infectious diseases. Healthcare professionals need to be aware of the vitamin D deficiency pandemic. Guidelines for sensible sun exposure and supplemental vitamin D of 800-1000 IU/day are needed.
Matti Narkia

Vitamin D intake to attain a desired serum 25-hydroxyvitamin D concentration -- Aloia e... - 0 views

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    Vitamin D intake to attain a desired serum 25-hydroxyvitamin D concentration. Aloia JF, Patel M, Dimaano R, Li-Ng M, Talwar SA, Mikhail M, Pollack S, Yeh JK. Am J Clin Nutr. 2008 Jun;87(6):1952-8. PMID: 18541590 The mean daily dose was 86 microg (3440 IU). The use of computer simulations to obtain the most participants within the range of 75-220 nmol/L predicted an optimal daily dose of 115 microg/d (4600 IU). No hypercalcemia or hypercalciuria was observed. CONCLUSIONS: Determination of the intake required to attain serum 25(OH)D concentrations >75 nmol/L must consider the wide variability in the dose-response curve and basal 25(OH)D concentrations. Projection of the dose-response curves observed in this convenience sample onto the population of the third National Health and Nutrition Examination Survey suggests a dose of 95 microg/d (3800 IU) for those above a 25(OH)D threshold of 55 nmol/L and a dose of 125 microg/d (5000 IU) for those below that threshold.
Matti Narkia

Summary of evidence-based review on vitamin D efficacy and safety in relation to bone h... - 0 views

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    Summary of evidence-based review on vitamin D efficacy and safety in relation to bone health. Cranney A, Weiler HA, O'Donnell S, Puil L. Am J Clin Nutr. 2008 Aug;88(2):513S-519S. Review. PMID: 18689393 We found inconsistent evidence of an association between serum 25-hydroxyvitamin D [25(OH)D] concentration and bone mineral content in infants and fair evidence of an association with bone mineral content or density in older children and older adults. The evidence of an association between serum 25(OH)D concentration and some clinical outcomes (fractures, performance measures) in postmenopausal women and older men was inconsistent, and the evidence of an association with falls was fair. We found good evidence of a positive effect of consuming vitamin D-fortified foods on 25(OH)D concentrations. The evidence for a benefit of vitamin D on falls and fractures varied. We found fair evidence that adults tolerated vitamin D at doses above current dietary reference intake levels, but we had no data on the association between long-term harms and higher doses of vitamin D.
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