beta-carotene and Hip-Fractures

Vitamin A is a generic term for compounds that have biological activity similar to that of retinol and includes carotenoids like β-carotene and α-carotene. Some studies suggest high dietary intake of vitamin A can increase bone fracture risk. This investigation involved a systematic review and meta-analysis examining the association between vitamin A and fracture risk. Published literature was searched to find studies that (1) involved human participants, (2) had prospective cohort or case-control study designs, (3) contained original quantitative data on associations between dietary intake of vitamin A and fractures, and (4) provided either risk ratios (RRs), odds ratios (ORs), or hazard ratios (HRs) with 95% confidence intervals (95% CIs) comparing various levels of vitamin A consumption to fracture risk. Thirteen studies met the review criteria. Meta-analyses indicated that risk of hip fracture was increased by high dietary intake of total vitamin A (RR = 1.29; 95% CI = 1.07-1.57) or retinol (RR = 1.23; 95% CI = 1.02-1.48). Hip fracture risk was reduced by high dietary intake of total carotene (RR = 0.62; 95% CI = 0.42-0.93), β-carotene (RR = 0.72; 95% CI = 0.58-0.89), or α-carotene (RR = 0.81; 95% CI = 0.67-0.97). Total fracture risk was not associated with any vitamin A compound. High intake of total vitamin A or retinol increased hip fracture risk, while high intake of some carotenoids reduced hip fracture risk.

Topics: beta Carotene; Case-Control Studies; Fractures, Bone; Hip Fractures; Humans; Prospective Studies; Risk Factors; Vitamin A

Epidemiological studies examining the association between β-carotene intake and risk of fracture have reported inconsistent findings. We conducted a meta-analysis to investigate the association between β-carotene intake and risk of fracture.. We systematically searched PubMed, EMBASE and Cochrane library databases for relevant articles that were published until December 2019. We also identified studies from reference lists of articles identified from the clinical databases. The frequentist and Bayesian random-effects model was used to synthesize data.. Nine studies with a total of 190,545 men and women, with an average age of 59.8 years, were included in this meta-analysis. For β-carotene intake (1.76-14.30 mg/day), the pooled risk ratio (RR) of any fracture was 0.67 (95% Credible Interval (CrI): 0.51-0.82; heterogeneity: P = 0.66, I. The present meta-analysis suggests that β-carotene intake was inversely associated with fracture risk, which was consistently observed for case-control and cohort studies. Randomized controlled trials are warranted to confirm this relationship.

Topics: Bayes Theorem; beta Carotene; China; Europe; Female; Hip Fractures; Humans; Male; Middle Aged

This meta-analysis evaluated the influence of dietary intake and blood level of vitamin A (total vitamin A, retinol or β-carotene) on total and hip fracture risk. Cohort studies published before July 2017 were selected through English-language literature searches in several databases. Relative risk (RR) with corresponding 95% confidence interval (CI) was used to evaluate the risk. Heterogeneity was checked by Chi-square and I² test. Sensitivity analysis and publication bias were also performed. For the association between retinol intake and total fracture risk, we performed subgroup analysis by sex, region, case ascertainment, education level, age at menopause and vitamin D intake. R software was used to complete all statistical analyses. A total of 319,077 participants over the age of 20 years were included. Higher dietary intake of retinol and total vitamin A may slightly decrease total fracture risk (RR with 95% CI: 0.95 (0.91, 1.00) and 0.94 (0.88, 0.99), respectively), and increase hip fracture risk (RR with 95% CI: 1.40 (1.02, 1.91) and 1.29 (1.06, 1.57), respectively). Lower blood level of retinol may slightly increase total fracture risk (RR with 95% CI: 1.11 (0.94, 1.30)) and hip fracture risk (RR with 95% CI: 1.27 (1.05, 1.53)). In addition, higher β-carotene intake was weakly associated with the increased risk of total fracture (RR with 95% CI: 1.07 (0.97, 1.17)). Our data suggest that vitamin A intake and level may differentially influence the risks of total and hip fractures. Clinical trials are warranted to confirm these results and assess the clinical applicability.

Topics: Adult; beta Carotene; Cohort Studies; Diet; Female; Hip Fractures; Humans; Male; Middle Aged; Risk Factors; Vitamin A; Vitamin A Deficiency; Young Adult

If osteoporosis is linked with vitamin A (Vit A) A consumption, millions of people could be affected.. A MEDLINE search was performed with keywords retinol, beta-carotene, and osteoporosis.. Of 20 clinical studies, 3 were randomized controlled trials (RCTs), 14 were observational studies, and 3 were case reports. Most (8) observational studies were cross-sectional. Oral retinoyl palmitate (RP) in high doses induces fractures and radiographic osteoporosis in animals. Retinol intake from diet or supplements is negatively associated with lumbar, femoral neck, and trochanter bone mineral density (BMD). There is a graded increase in relative risk of hip fracture with increasing retinol intake, attributable primarily to retinol (either from diet or supplements) but not beta-carotene intake. Higher serum retinol levels are associated with higher risk of any fracture and with higher risk of hip fracture, whereas there is no evidence of harm associated with beta-carotene intake. The few RCTs involve serum markers of bone metabolism, not bone density or fracture outcomes. Observational studies are generally consistent in finding harm from either dietary or supplemental retinol intake on BMD and hip fracture risk. Total Vit A intake is more important than source in determining harm. Adverse effects may occur at a level of retinol intake that is only about twice the current recommendation for adult females.. It is not yet possible to set a specific level of retinol intake above which bone health is compromised. Pending further investigation, Vit A supplements should not be used with the express goal of improving bone health.

Topics: Aged; Animals; beta Carotene; Body Mass Index; Bone and Bones; Bone Density; Cohort Studies; Female; Fractures, Bone; Hip Fractures; Humans; Male; Osteoporosis; Primary Prevention; Randomized Controlled Trials as Topic; Risk Factors; Time Factors; United States; Vitamin A

Mechanism studies have suggested that carotenoids may benefit bone health due to their antioxidant properties, but epidemiological data on their effects on risk of hip fracture are sparse.. To explore the relationships between dietary total and specific carotenoids and the risk of hip fracture in a middle-aged and elderly Chinese population.. A case-control study of 1070 patients with hip fractures (diagnosed within 2 weeks) aged 55-80 years and 1070 age- (within 3 years) and gender-matched controls was conducted in Guangdong, China between 2009 and 2015. Information on dietary carotenoid intake was assessed using a 79-item food frequency questionnaire administered in face-to-face interviews, and general information was collected using structured questionnaires. The univariate and multivariate conditional logistic regression models were applied to analyze the associations.. Higher intakes of both total and some specific carotenoids (including β-carotene, β-cryptoxanthin and lutein/zeaxanthin) were significantly associated with a lower risk of hip fracture (all p trends <0.01). Compared with the lowest quartile of carotenoids, the multivariate-adjusted odds ratios and 95% confidential intervals of the highest quartile were 0.44 (0.29, 0.68) (total carotenoids), 0.50 (0.29, 0.69) (β-carotene), 0.55 (0.38, 0.80) (β-cryptoxanthin) and 0.40 (0.27, 0.59) (lutein/zeaxanthin), respectively. There were no statistically significant associations between α-carotene and lycopene intakes and hip fracture risk after adjustment for various confounding variables.. These results suggest that the consumption of carotenoids may be protective against hip fracture in middle-aged and elderly Chinese adults.

Topics: Aged; Aged, 80 and over; Antioxidants; beta Carotene; Carotenoids; Case-Control Studies; China; Female; Hip Fractures; Humans; Male; Middle Aged; Risk; Surveys and Questionnaires

The role of oxidative stress in skeletal health is unclear. The present study investigated whether a high dietary intake of antioxidant nutrients (vitamins C and E, β-carotene, animal-derived vitamin A, retinol equivalents, Zn and Se) is associated with a reduced risk of hip fracture in elderly Chinese. This 1:1 matched case-control study involved 726 elderly Chinese with hip fracture and 726 control subjects, recruited between June 2009 and May 2013. Face-to-face interviews were conducted to determine habitual dietary intakes of the above-mentioned seven nutrients based on a seventy-nine-item FFQ and information on various covariates, and an antioxidant score was calculated. After adjustment for potential covariates, dose-dependent inverse associations were observed between the dietary intake of vitamin C, vitamin E, β-carotene, and Se and antioxidant score and the risk of hip fracture (P for trend ≤ 0·005). The OR of hip fracture for the highest (v. lowest) quartile of intake were 0·39 (95 % CI 0·28, 0·56) for vitamin C, 0·23 (95 % CI 0·16, 0·33) for vitamin E, 0·51 (95 % CI 0·36, 0·73) for β-carotene, 0·43 (95 % CI 0·26, 0·70) for Se and 0·24 (95 % CI 0·17, 0·36) for the antioxidant score. A moderate-to-high dietary intake of retinol equivalents in quartiles 2-4 (v. 1) was found to be associated with a lower risk of hip fracture (OR range: 0·51-0·63, P< 0·05). No significant association was observed between dietary Zn or animal-derived vitamin A intake and hip fracture risk (P for trend >0·20). In conclusion, a higher dietary intake of vitamins C and E, β-carotene, and Se and a moderate-to-high dietary intake of retinol equivalents are associated with a lower risk of hip fracture in elderly Chinese.

Topics: Aged; Antioxidants; Ascorbic Acid; Asian People; beta Carotene; Case-Control Studies; China; Female; Hip Fractures; Humans; Middle Aged; Odds Ratio; Osteoporosis; Oxidative Stress; Risk; Risk Factors; Selenium; Trace Elements; Vitamin A; Vitamin E; Vitamins; Zinc

Topics: beta Carotene; Bone Density; Dose-Response Relationship, Drug; Health Promotion; Hip Fractures; Humans; Vitamin A

There is debate about the possible deleterious effect of excessive vitamin A exposure on fracture risk. In this nested case control study in older women (312 cases and 934 controls), serum retinol, retinyl palmitate, and beta-carotene were not associated with fracture risk, and there was no evidence of excess risk with multivitamin or cod liver oil supplementation.. Recent studies have suggested that higher vitamin A intake may account for a component of fracture risk within the general population and that supplemental vitamin A may be harmful even within recommended limits. No studies have examined the relationship between biochemical retinol status and fracture in older women.. We examined serum retinol, retinyl palmitate, and beta-carotene as predictors of incident hip and other fractures in a large prospective study of British women over the age of 75 years (n = 2606, 312 incident osteoporotic fractures, 92 incident hip fractures; mean follow-up duration, 3.7 years). Fasting blood samples (9:00-11:00 a.m.) were collected at baseline. Using a case-control design (three controls per case), serum retinol, retinyl palmitate, and beta-carotene were assessed as univariate predictors of incident osteoporotic fracture or hip fracture. Baseline BMD at the total hip, age, 25(OH)D, serum beta Crosslaps, bone-specific alkaline phosphatase, weight, height, and smoking were considered as covariates in a multivariate model.. Serum retinol, retinyl palmitate, and beta-carotene were not significant univariate predictors of either hip fracture or any fracture (all p > 0.05; Cox proportional hazards regression). For all osteoporotic fractures, the hazard ratio (HR) was 0.92 (95% CI, 0.81-1.05) per 1 SD increase in serum retinol. Risk of any osteoporotic fracture was slightly less in the highest quartile of serum retinol compared with the lowest quartile (HR, 0.85; 95% CI, 0.69-1.05; p = 0.132) There was a tendency for increased serum retinol to predict benefit rather than harm in terms of BMD (r = 0.09, p = 0.002). Multivitamin or cod liver oil supplementation was associated with a significantly lower risk of any fracture (HR, 0.76; 95% CI, 0.60-0.96; p = 0.021). In multivariate analysis, only age, total hip BMD, and weight were associated with fracture risk (p < 0.05).. We found no evidence to support any skeletal harm associated with increased serum indices of retinol exposure or modest retinol supplementation in this population.

Topics: Aged; Alkaline Phosphatase; beta Carotene; Body Height; Body Weight; Bone and Bones; Bone Density; Case-Control Studies; Dietary Supplements; Diterpenes; Female; Hip Fractures; Humans; Multivariate Analysis; Osteoporosis; Proportional Hazards Models; Regression Analysis; Retinoids; Retinyl Esters; Risk Factors; Time Factors; Vitamin A

Although studies in animals and epidemiologic studies have indicated that a high vitamin A intake is associated with increased bone fragility, no biologic marker of vitamin A status has thus far been used to assess the risk of fractures in humans.. We enrolled 2322 men, 49 to 51 years of age, in a population-based, longitudinal cohort study. Serum retinol and beta carotene were analyzed in samples obtained at enrollment. Fractures were documented in 266 men during 30 years of follow-up. Cox regression analysis was used to determine the risk of fracture according to the serum retinol level.. The risk of fracture was highest among men with the highest levels of serum retinol. Multivariate analysis of the risk of fracture in the highest quintile for serum retinol (>75.62 microg per deciliter [2.64 micromol per liter]) as compared with the middle quintile (62.16 to 67.60 microg per deciliter [2.17 to 2.36 micromol per liter]) showed that the rate ratio was 1.64 (95 percent confidence interval, 1.12 to 2.41) for any fracture and 2.47 (95 percent confidence interval, 1.15 to 5.28) for hip fracture. The risk of fracture was further increased within the highest quintile for serum retinol. Men with retinol levels in the 99th percentile (>103.12 microg per deciliter [3.60 micromol per liter]) had an overall risk of fracture that exceeded the risk among men with lower levels by a factor of seven (P<0.001). The level of serum beta carotene was not associated with the risk of fracture.. 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.

Topics: beta Carotene; Body Mass Index; Dose-Response Relationship, Drug; Fractures, Bone; Hip Fractures; Humans; Longitudinal Studies; Male; Middle Aged; Multivariate Analysis; Osteoporosis; Proportional Hazards Models; Risk Factors; Vitamin A

Ingestion of toxic amounts of vitamin A affects bone remodeling and can have adverse skeletal effects in animals. The possibility has been raised that long-term high vitamin A intake could contribute to fracture risk in humans.. To assess the relationship between high vitamin A intake from foods and supplements and risk of hip fracture among postmenopausal women.. Prospective analysis begun in 1980 with 18 years of follow-up within the Nurses' Health Study.. General community of registered nurses within 11 US states.. A total of 72 337 postmenopausal women aged 34 to 77 years.. Incident hip fractures resulting from low or moderate trauma, analyzed by quintiles of vitamin A intake and by use of multivitamins and vitamin A supplements, assessed at baseline and updated during follow-up.. From 1980 to 1998, 603 incident hip fractures resulting from low or moderate trauma were identified. After controlling for confounding factors, women in the highest quintile of total vitamin A intake (>/=3000 microgram/d of retinol equivalents [RE]) had a significantly elevated relative risk (RR) of hip fracture (RR, 1.48; 95% confidence interval [CI], 1.05-2.07; P for trend =.003) compared with women in the lowest quintile of intake (<1250 microgram/d of RE). This increased risk was attributable primarily to retinol (RR, 1.89; 95% CI, 1.33-2.68; P for trend <.001 comparing >/=2000 microgram/d vs <500 microgram/d). The association of high retinol intake with hip fracture was attenuated among women using postmenopausal estrogens. Beta carotene did not contribute significantly to fracture risk (RR, 1.22; 95% CI, 0.90-1.66; P for trend =.10 comparing >/=6300 microgram/d vs <2550 microgram/d). Women currently taking a specific vitamin A supplement had a nonsignificant 40% increased risk of hip fracture (RR, 1.40; 95% CI, 0.99-1.99) compared with those not taking that supplement, and, among women not taking supplemental vitamin A, retinol from food was significantly associated with fracture risk (RR, 1.69; 95% CI, 1.05-2.74; P for trend =.05 comparing >/=1000 microgram/d vs <400 microgram/d).. Long-term intake of a diet high in retinol may promote the development of osteoporotic hip fractures in women. The amounts of retinol in fortified foods and vitamin supplements may need to be reassessed.

Topics: Adult; Aged; beta Carotene; Dietary Supplements; Female; Hip Fractures; Humans; Middle Aged; Nutrition Assessment; Osteoporosis; Postmenopause; Proportional Hazards Models; Prospective Studies; Risk Factors; Vitamin A

Topics: beta Carotene; Carotenoids; Diet; Female; Hip Fractures; Humans; Nutrition Policy; Osteoporosis; Vitamin A