Serum Retinol Levels and the Risk of Fracture

Michaëlsson, Karl; Lithell, Hans; Vessby, Bengt; Melhus, Håkan

doi:10.1056/nejmoa021171

Cited by 330 publications

(286 citation statements)

References 50 publications

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“…Recently there has been growing concern regarding the chronic effects of subclinical vitamin A toxicity. In adults, a long-term intake of preformed vitamin A of only twice the RDA has been associated with osteoporosis and hip fractures, presumably by stimulating bone resorption and inhibiting the ability of vitamin D to prevent Ca loss from the bone (31)(32)(33) . The long-term effect of periodic high-dose vitamin A supplements on the bone health of young children is not known, especially those who are vitamin A sufficient but compromised in terms of other micronutrients.…”

Section: Discussionmentioning

confidence: 99%

Serum retinol in 1–6-year-old children from a low socio-economic South African community with a high intake of liver: implications for blanket vitamin A supplementation

Stuijvenberg

Schoeman

Lombard

et al. 2011

Public Health Nutr.

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Objective: To assess serum retinol, liver intake patterns, breast-feeding history and anthropometric status in pre-school children of a low socio-economic community where liver is regularly consumed. Design: Cross-sectional study. Setting: Northern Cape Province, South Africa. Subjects: Children aged 1-6 years (n 243) who attended the local primary healthcare facility and had not received a vitamin A supplement in the 6 months preceding the study. Non-pregnant female caregivers (n 225), below 50 years of age, were also assessed. Results: Despite stunting, underweight and wasting being prevalent in 40?5 %, 23?1 % and 8?4 % of the children, only 5?8 % had serum retinol concentrations , 20 mg/dl, which is in sharp contrast to the national prevalence of 63?6 %. None of the caregivers were vitamin A deficient. Liver was eaten by 89?2 % of children, with 87 % of households eating liver at least once monthly and 30 % eating it at least once weekly; liver was introduced into the diet of the children at a median age of 18 months. Ninety-three per cent of the children were being breast-fed or had been breast-fed in the past; children were breast-fed to a median age of 18 months. A significant negative correlation was found between educational level of the caregiver and frequency of liver intake (r 5 20?143, P50?032). There was no correlation between serum retinol and indicators of anthropometric or socio-economic status. Conclusions: The blanket approach in applying the national vitamin A supplementation programme may not be appropriate for all areas in the country, even though the community may be poor and undernourished.

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Section: Discussionmentioning

confidence: 99%

Serum retinol in 1–6-year-old children from a low socio-economic South African community with a high intake of liver: implications for blanket vitamin A supplementation

Stuijvenberg

Schoeman

Lombard

et al. 2011

Public Health Nutr.

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“…Addition of 9cRA to 1,25D treatment completely prevented the weight loss and kidney calcification seen with 1,25D treatment alone, without decreasing the effectiveness of 1,25D treatment against lung tumor incidence and multiplicity. An effect of retinoids on calcium homeostasis has been shown more clearly in studies investigating the association between vitamin A and fracture risk, [45][46][47][48] and the influence of retinoids on vitamin D regulation of serum calcium and bone mineral homeostasis. 35,49,50 Unfortunately, we were unable to obtain sufficient data to report serum or urine calcium levels in our study.…”

Section: Discussionmentioning

confidence: 99%

Inhibition of lung carcinogenesis by 1α,25‐dihydroxyvitamin D₃ and 9‐cis retinoic acid in the A/J mouse model: Evidence of retinoid mitigation of vitamin D toxicity

Mernitz

Smith

Wood

et al. 2007

Intl Journal of Cancer

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9-cis-Retinoic acid (9cRA) and 1a, 25-dihydroxyvitamin D 3 (1,25D) show promise as potential chemopreventive agents. We examined 9cRA and 1,25D, alone and in combination, for their potential to inhibit carcinogen (NNK)-induced lung carcinogenesis in A/J mice. A/J mice (n 5 14/group) were treated with 9cRA (7.5, 15, or 30 mg/kg diet), 1,25D (2.5 or 5.0 lg/kg diet), or a combination of 9cRA (15 mg/kg diet) plus 1,25D (2.5 lg/kg diet) for 3 weeks before and 17 weeks after carcinogen injection. Lung tumor incidence, tumor multiplicity, plasma 1,25D levels and kidney expression of vitamin D 24-hydroxylase (CYP24) were determined. Compared to carcinogen-injected controls, mice receiving 9cRA supplementation had significantly lower tumor multiplicity at all doses (decreased 68-85%), with body weight loss at the higher doses of 9cRA. Mice receiving 1,25D supplementation had significantly lower tumor incidence (decreased 36 and 82%) and tumor multiplicity (decreased 85 and 98%), but experienced significant body weight loss, kidney calcium deposition, elevated kidney CYP24 expression and decreased fasting plasma 1,25D levels. Although, there was no apparent influence on chemopreventive efficacy, addition of 9cRA to 1,25D treatment effectively prevented the weight loss and kidney calcification associated with 1,25D treatment alone. These data demonstrate that 9cRA and 1,25D, alone or combined, can inhibit lung tumor promotion in the A/J mouse model. Combining 1,25D with 9cRA has the potential to mitigate the toxicity of 1,25D, while preserving the significant effect of 1,25D treatment against lung carcinogenesis. The underlying mechanism behind this effect does not appear to be related to retinoid modulation of vitamin D catabolism. ' 2006 Wiley-Liss, Inc.Key words: lung cancer; 9-cis retinoic acid; 1a,25-dihydroxyvitamin D 3Chemoprevention by diet or drug intervention may offer a realistic and practical means of modifying the risk of lung cancer, the leading cause of cancer deaths in both men and women in the United States. 1 Two classes of chemopreventive compounds that have been considered are the retinoids and the active form of vitamin D, 1a,25-dihydroxyvitamin D 3 (1,25D, also calcitriol).Retinoids are required for proper differentiation of lung and upper airway epithelium, 2 and both 9-cis retinoic acid (9cRA, also 9-cis tretinoin) and all-trans retinoic acid have been shown to inhibit cell growth and proliferation in lung cancer cell lines. 3 Studies in animal models of lung cancer suggest that retinoids may be effective in cancer chemoprevention in vivo, but results have varied with species, dose and timing of treatment in relation to induction of carcinogenesis. [4][5][6] In human lung cancer, epidemiological evidence supports a role for vitamin A-rich foods and supplements in protection against the development of lung cancer in smokers and nonsmokers alike 7 ; however, clinical trials assessing the efficacy of retinoid supplementation against lung cancer have yielded inconsistent and inconclusive results. [8][...

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“…A vitamina A é necessária para o crescimento ósseo normal; entretanto, ingestões acima de 1.500µ/dia de retinol foram associadas a menores DMO e maiores riscos de fraturas nas populações americanas e suecas (50) . Mesmo assim, não é possível determinar níveis seguros de ingestões adequadas de vitamina A, acima dos quais a saúde óssea seria comprometida (45) .…”

Section: Papel Das Vitaminas Na Saúde óSseaunclassified

Impacto dos nutrientes na saúde óssea: novas tendências

Morais

Burgos

2007

Rev. bras. ortop.

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A nutrição é fator importante modificável no desenvolvimento/manutenção da massa óssea (MO) e prevenção da osteoporose. Esta é uma doença caracterizada por decrés-cimo na massa esquelética e elevação da suscetibilidade a fraturas. O desenvolvimento do pico de massa óssea (PMO) é ainda o maior determinante dessa condição. Por isso, alterações com a idade sinalizam a importância da manutenção de nutrição adequada durante o desenvolvimento desse pico. Indivíduos que atingiram elevado PMO

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Serum Retinol Levels and the Risk of Fracture

Abstract: Our findings, which are consistent with the results of studies in animals, as well as in vitro and epidemiologic dietary studies, suggest that current levels of vitamin A supplementation and food fortification in many Western countries may need to be reassessed.

Cited by 330 publications

References 50 publications

Serum retinol in 1–6-year-old children from a low socio-economic South African community with a high intake of liver: implications for blanket vitamin A supplementation

Serum retinol in 1–6-year-old children from a low socio-economic South African community with a high intake of liver: implications for blanket vitamin A supplementation

Inhibition of lung carcinogenesis by 1α,25‐dihydroxyvitamin D₃ and 9‐cis retinoic acid in the A/J mouse model: Evidence of retinoid mitigation of vitamin D toxicity

Impacto dos nutrientes na saúde óssea: novas tendências

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Serum Retinol Levels and the Risk of Fracture

Abstract: Our findings, which are consistent with the results of studies in animals, as well as in vitro and epidemiologic dietary studies, suggest that current levels of vitamin A supplementation and food fortification in many Western countries may need to be reassessed.

Cited by 330 publications

References 50 publications

Serum retinol in 1–6-year-old children from a low socio-economic South African community with a high intake of liver: implications for blanket vitamin A supplementation

Serum retinol in 1–6-year-old children from a low socio-economic South African community with a high intake of liver: implications for blanket vitamin A supplementation

Inhibition of lung carcinogenesis by 1α,25‐dihydroxyvitamin D3 and 9‐cis retinoic acid in the A/J mouse model: Evidence of retinoid mitigation of vitamin D toxicity

Impacto dos nutrientes na saúde óssea: novas tendências

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Inhibition of lung carcinogenesis by 1α,25‐dihydroxyvitamin D₃ and 9‐cis retinoic acid in the A/J mouse model: Evidence of retinoid mitigation of vitamin D toxicity