Calcium Intake and 10-Year Weight Change in Middle-Aged Adults

Objective

The goal of this study was to examine the purported effects of calcium on modulating body weight.

Design

Retrospective data was used to assess the relationship between calcium intake and weight change over an 8- to 12-year period among middle-aged adults.

Subjects

Participants were 10,591 men and women aged 53 to 57 years recruited during 2000-2002.

Statistical Analysis

Linear regression was used to model associations of 10-year weight change and calcium intake, adjusted for weight at age 45 years, energy intake, physical activity, and other factors.

Results

Calcium intake was associated with 10-year weight change only in women. Women with current calcium supplement dose of >500 mg/day had a 10-year weight gain of 5.1 kg (95% confidence interval 4.7 to 5.5) compared to 6.9 kg (95% confidence interval 6.5 to 7.4) among nonusers (P for trend=0.001). Trends were similar for total calcium intake from diet plus supplements (P for trend=0.001). Dietary calcium alone had no significant effect on 10-year weight change.

Conclusions

Increasing total calcium intake, in the form of calcium supplementation, may be beneficial to weight maintenance, especially in women during midlife.     

Calcium intake in the United States from dietary and supplemental sources across adult age groups: new estimates from the National Health and Nutrition Examination Survey 2003-2006

Background

Adequate lifelong calcium intake is essential in optimizing bone health. Recent National Health and Nutrition Examination Survey data were used to quantify variation in calcium intake across adult age groups and to relate age-associated changes in calcium intake with energy intake. Additional goals were to assess differences in dietary calcium intake between supplemental calcium users and nonusers and to evaluate associations between age and calcium density in the diet.

Design

This cross-sectional analysis determined calcium and energy intake for National Health and Nutrition Examination Survey respondents during 2003-2006. Diet was assessed with 24-hour recall and supplement use via questionnaire. Trends in median intakes for dietary calcium, total calcium, and energy across age categories were assessed using survey analysis methods. Nutrient density was represented using calcium to energy intake ratios.

Results

The analyses included data from 9,475 adults. When compared to the 19- to 30-year age group, median dietary calcium intake was lower in the ≥81-year age group by 23% in men (P<0.001) and by 14% in women (P=0.003). These reductions coincided with 35% and 28% decreases, respectively, in median energy intake (P<0.001 for each sex). In contrast, the frequency of calcium supplement use increased (P<0.001) with age in both men and women. Yet, among female supplement users, the decline in median dietary calcium intake was greater than in nonusers (P=0.02). Calcium density in the diet significantly increased relative to age in men and women (P<0.001 for each sex); however, dietary and total calcium to energy ratios were insufficient to meet target ratios inferred by adequate intake standards after age 50 years.

Conclusions

Although supplemental calcium use and calcium density were highest in older age groups, they were not sufficient in meeting recommended levels. New approaches to increasing the frequency and level of calcium supplement use to enhance calcium density in diets may be necessary to reduce osteoporosis risk among older Americans.     

Dietary intake of vitamin B-6, plasma pyridoxal 5'-phosphate, and homocysteine in Puerto Rican adults

Background

Vitamin B-6 is an important cofactor in many metabolic processes. However, vitamin B-6 intake and plasma status have not been well studied in the Puerto Rican population, a group with documented health disparities.

Objective

To assess dietary intake of vitamin B-6, food sources, and plasma status of pyridoxal 5′-phosphate (PLP), and their associations with plasma homocysteine in 1,236 Puerto Rican adults, aged 45 to 75 years, living in the greater Boston area.

Design

Baseline data were analyzed cross-sectionally.

Method

Questionnaire data were collected by home interview. Dietary intake was assessed with a semiquantitative food frequency questionnaire. Plasma PLP and homocysteine were assayed from blood samples collected in the home.

Results

The mean daily intake of vitamin B-6 was 2.90±1.28 mg for men and 2.61±1.29 mg for women (P<0.001). Approximately 11% were deficient (PLP <4.94 ng/mL [PLP <20 nmol/L]) and another 17% insufficient (PLP ≥4.94 but <7.41 ng/mL [PLP ≥20 but <30 nmol/L]). Household income below the poverty threshold, physical inactivity, and current smoking were significantly associated with lower plasma PLP (P<0.05). Food groups contributing most to vitamin B-6 intake included ready-to-eat cereals, poultry, rice, potatoes, and dried beans. However, only intake of ready-to-eat cereals and use of supplements with vitamin B-6 were significantly associated with plasma PLP sufficiency (≥7.41 vs <7.41 ng/mL [PLP ≥30 vs <30 nmol/L], P<0.01). Both vitamin B-6 intake and PLP were significantly associated with plasma total homocysteine (P<0.001). The association between PLP and homocysteine remained statistically significant after further adjustment for plasma vitamin B-12 and folate (P=0.028).

Conclusions

Given the known importance of vitamin B-6 to health, the high prevalence of low vitamin B-6 status in this Puerto Rican population is of concern. Further work is needed to clarify the potential role that insufficient vitamin B-6 may have in relation to the observed health disparities in this population.     

A comparison of micronutrient inadequacy and risk of high micronutrient intakes among vitamin and mineral supplement users and nonusers in Canada

Although supplement use is prevalent in North America, there is little information on how supplements affect the prevalence of nutrient adequacy or risk of intakes greater than the tolerable upper intake level (UL). The objectives of this study were to compare the prevalence of nutrient adequacy and percent of intakes greater than the UL from diet alone between supplement users and nonusers and determine the contribution of supplements to nutrient intakes. Dietary intakes (24-h recall) and supplement use (previous 30 d) from respondents ≥1 y in the Canadian Community Health Survey 2.2 (n = 34,381) were used to estimate the prevalence of nutrient adequacy and intakes greater than the UL. Software for Intake Distribution Evaluation was used to estimate usual intakes. The prevalence of nutrient adequacy from diet alone was not significantly higher among supplement users than nonusers for any nutrient. Based on diet alone, children 1-13 y had a low prevalence of nutrient adequacy (<30%) except for vitamin D and calcium. Among respondents ≥14 y, inadequacies of vitamins A and D, calcium, and magnesium were >30%. For other nutrients, there was a low prevalence of nutrient adequacy. There were no nutrient intakes greater than the UL from diet alone, except zinc in children. When supplements were included, ≥10% of users in some age/sex groups had intakes of vitamins A and C, niacin, folic acid, iron, zinc, and magnesium greater than the UL, reaching >80% for vitamin A and niacin in children. In conclusion, from diet alone, the prevalence of nutrient adequacy was low for most nutrients except for calcium, magnesium, and vitamins A and D. For most nutrients, supplement users were not at greater risk of inadequacy than nonusers; supplement use sometimes led to intakes greater than the UL.     

Older adults who use vitamin/mineral supplements differ from nonusers in nutrient intake adequacy and dietary attitudes

OBJECTIVE: To measure nutrient intake adequacy of vitamin/mineral supplement users and nonusers aged 51 years and older, determine the efficacy of supplement practices in compensating for dietary deficits, and identify predictors of supplement use. DESIGN: Analyses of two 24-hour recalls, demographic variables, and attitude questions collected during the Continuing Survey of Food Intakes by Individuals and Diet and Health Knowledge Survey in 1994 to 1996. Data were weighted to be representative of older Americans. SUBJECTS: Four thousand three hundred eighty-four adults aged 51 years and older (1,777 daily supplement users, 428 infrequent users, and 2,179 nonusers) residing in households in the United States. STATISTICAL ANALYSES: Usual nutrient intake distributions were estimated using the Iowa State University method. The Estimated Average Requirement (EAR) cutpoint method was applied to determine the proportion of older adults not meeting requirements before and after accounting for nutrient intake from supplements. Student t tests were used to assess differences between users and nonusers. Logistic regression was used to determine sociodemographic and attitudinal predictors of supplement use. RESULTS: For one or more of the sex-age groups studied, a significantly smaller proportion of supplement users than nonusers had intakes from food alone below the EAR for vitamins A, B-6, and C; folate; zinc; and magnesium. Even so, less than 50% of both users and nonusers met the EAR for folate, vitamin E, and magnesium from food sources alone. Overall, supplements improved the nutrient intake of older adults. After accounting for the contribution of supplements, 80% or more of users met the EAR for vitamins A, B-6, B-12, C, and E; folate; iron; and zinc, but not magnesium. However, some supplement users, particularly men, exceeded Tolerable Upper Intake Levels for iron and zinc and a small percentage of women exceeded the Tolerable Upper Intake Level for vitamin A. Significant sociodemographic factors related to supplement use for older men were age group, metropolitan area, and educational status. Race, region, smoking status, and vegetarian status were significant factors for women. Attitude about the importance of following a healthful diet was a consistent predictor of supplement use for both men and women. CONCLUSIONS: A large proportion of older adults do not consume sufficient amounts of many nutrients from foods alone. Supplements compensate to some extent, but only an estimated half of this population uses them daily. These widespread inadequacies should be considered when developing recommendations for supplement use for clients in this age group. Modifying dietary attitudes may result in a higher rate of supplement use in this at-risk population.     

Assessment of Nutrient Adequacy with Supplement Use in a Sample of Healthy College Students

Objectives: Limited information is available on the nutritional status and the impact of supplements on nutrient adequacy in college students. This study aimed to assess nutritional status and evaluate the contribution of supplement use to overall nutrient adequacy in a sample of healthy college students.

Methods: Sixty subjects (40 women and 20 men) were randomly recruited from those attending the University of Connecticut. Food records were collected over 30 consecutive days for each subject. In addition, health and lifestyle information was collected at the beginning and end of the study period.

Results: After excluding misreporting, only 44 subjects were eligible for assessing nutritional status. More than 40% of female students had intakes below the estimated average requirements for vitamins D and E, calcium, and magnesium. Supplement users had significantly higher average intakes than nonusers from dietary sources for protein, folate, niacin, vitamin E, magnesium, and zinc (p < 0.05). With the addition of supplements, supplement users consumed significantly more for all nutrient intakes except vitamin A than nonusers (p < 0.05). Nutritional adequacy of supplement users was significantly higher for vitamins D and E and magnesium compared with nonusers (p < 0.05).

Conclusions: Overall, men and women were consuming intakes below adequacy for most nutrients, and supplement usage increased nutrient intake and adequacy levels in this young adult population.     

Vitamin D intake of Dutch infants from the combination of (fortified) foods,infant formula,and dietary supplements

Purpose

Due to changes in the Dutch fortification policy for vitamin D and the vitamin D supplementation advice for infants (10-μg/d for 0–4 year olds), a partially virtual scenario study was conducted to evaluate the risk of excessive vitamin D intake assigning all infants to a 100 % adherence to the supplementation advice and considering the current fortification practice.

Methods

Food consumption data from the Nutrition Intake Study (2002; N = 941, 7–19 months) were combined with Dutch food composition data from 2011 to estimate vitamin D intake from (fortified) foods. For infants 0–6 months of age, the consumption volume infant formula was estimated from energy requirement and body weight. All subjects were assigned to take a daily 10 µg vitamin D supplement, according the Dutch supplementation advice for infants. Habitual vitamin D intake was estimated using the Statistical Program to Assess Dietary Exposure and compared with the tolerable upper intake levels (ULs) set by the European Food Safety Authority.

Results

The median habitual total vitamin D intake was 16–22 µg/day for infants aged 0–6 months (increasing with age) and 13–21 µg/day for infants aged 7–19 months (decreasing with age). About 4–12 % of infants aged 7–11 months exceeded the UL. At the 99th percentile, the intake was 2–4 µg above the UL, depending on age. Infants aged 0–6 and 12–19 months did not exceed the UL.

Conclusions

In case of combined intake from infant formula, (fortified) foods, and supplements, vitamin D intakes above the UL are possible among some infants during a limited time period.

     

Effect of withdrawal of calcium and vitamin D supplements on bone mass in elderly men and women

BACKGROUND: Supplementation with calcium and vitamin D reduces bone loss and prevents fractures in elderly people, but it is not known whether any lasting benefit remains if the supplements are discontinued. OBJECTIVE: The objective was to determine whether gains in bone mineral density (BMD) induced by calcium and vitamin D supplementation persist after supplement withdrawal. DESIGN: Two-hundred ninety-five healthy, elderly men and women (aged >/=68 y) who had completed a 3-y randomized, placebo-controlled trial of calcium and vitamin D supplementation were followed for an additional 2 y during which no study supplements were given. BMD was measured by dual-energy X-ray absorptiometry, and biochemical variables related to calcium metabolism and bone turnover were measured. RESULTS: In the 128 men, supplement-induced increases in spinal and femoral neck BMD were lost within 2 y of supplement discontinuation, but small benefits in total-body BMD remained. In the 167 women, there were no lasting benefits in total-body BMD or at any bone site. Consistent with the observations on BMD, the bone turnover rates in both men and women (as measured by serum osteocalcin concentrations) returned to their original higher concentrations within the same 2-y period. CONCLUSION: Discontinued calcium and vitamin D supplementation has limited cumulative effect on bone mass in men and women aged >/=68 y.     

Combined oral contraceptive use among breastfeeding women: a systematic review

Background

Postpartum women need effective contraception, but using hormonal contraceptives may affect breastfeeding performance and infant health outcomes.

Study design

We searched the MEDLINE and Cochrane databases for all articles published through May 2009 for primary research studies that investigated clinical outcomes among breastfeeding women who used hormonal contraception or their infants.

Results

Three randomized controlled trials reported decreased mean duration of breastfeeding and higher rates of supplemental feeding among combined oral contraceptive (COC) users than among nonusers, while one multicountry trial found no differences in these parameters. Only one study demonstrated lower average weights during the first year of life for infants whose mothers used COCs while breastfeeding. None of the eight studies, four of which were observational, included in this review documented adverse infant health outcomes.

Conclusions

Limited evidence demonstrates an inconsistent effect of COC on breastfeeding duration and success. The evidence is inadequate to determine whether a mother's use of these drugs affects breastfeeding duration or the infant's health.     

Prospective study of weight change in new adolescent users of DMPA, NET-EN, COCs, nonusers and discontinuers of hormonal contraception

Background

Weight gain is commonly reported as a side effect of hormonal contraception and can lead to method discontinuation or reluctance to initiate the method. The purpose of this study was to investigate weight change in adolescent (aged 15-19 years) users of depot-medroxyprogesterone acetate (DMPA), norethisterone enanthate (NET-EN), combined oral contraceptives (COCs) and discontinuers of these methods as compared to nonusers of hormonal contraception.

Study Design

This longitudinal study recruited initiators of DMPA (n=115), NET-EN (n=115), COCs (n=116) and nonusers of contraception (n=144). Participants were followed up for 4-5 years, and details of current contraceptive method, including switching, discontinuing and/or starting hormonal methods were documented at each 6-monthly visit. Women were classified according to their contraceptive histories on completion of the study, and injectable users were combined into one group for analysis. Height, weight and self-reported dieting were recorded at each visit.

Results

There was no difference in mean age or weight between the groups at baseline. Women using DMPA or NET-EN throughout, or switching between the two, had gained an average of 6.2 kg compared to average increases of 2.3 kg in the COC group, 2.8 kg in nonusers and 2.8 kg among discontinued users of any method (p=.02). There was no evidence of a difference in weight gain between women classified as nonobese or classified as overweight/obese in any of the four study groups at baseline.

Conclusion

There is fairly strong evidence that adolescent contraceptive hormonal injectable users appear to gain more weight than COC users, discontinuers and nonusers of contraception.     

Risk of smoking and body mass index for incidence of diabetes mellitus in a rural Japanese population

Objective

To assess the risk of smoking, body mass index (BMI), and both for incidence of diabetes in a rural Japanese population.

Method

This study was a 10.1-year cohort study of 2070 men and 3802 women aged 40-69 years without diabetes at baseline who underwent a health check-up at one central hospital in Nagano Prefecture. Participants were classified according to a combination of smoking status and BMI. Participants were followed from 1990 to 2006. The incidence of diabetes was determined from fasting and random levels of plasma glucose, HbA_1c levels or being under medical treatment for diabetes.

Results

Diabetes developed in 595 of the participants during 59,111 person-years of follow-up. In men, the multivariable-adjusted hazard ratios for incidence of diabetes compared with non-smokers of normal weight were as follows: 3.36 (2.02-5.60) in current smokers with normal weight and 1.70 (0.87-3.34) and 3.93 (2.22-6.96) in obese non-smokers and obese current smokers, respectively. In men the population-attributable fraction of diabetes onset due to current smoking, obesity and both were 22.0%, 2.5% and 11.2%, respectively.

Conclusion

Regardless of BMI, smoking is an important risk factor for diabetes in male populations with a high prevalence of smoking.     

The use of dietary supplements among older persons in Southern Germany — Results from the KORA-age study

Objectives

Current population-based surveys in Europe on the prevalence of dietary supplement (DS) use in older individuals are scarce. The aim of the present study was to investigate patterns, prevalence and determinants of non-herbal DS use in aged subjects. Furthermore, the intake amounts of vitamins and minerals from supplements were assessed.

Design

Cross-sectional.

Setting

Data on supplement use were available from an age- and sex-stratified random sample of the German population-based KORA (Cooperative Health Research in the Region of Augsburg)-Age study.

Participants

1,079 persons who were born in or before the year 1943.

Measurements

Use of dietary supplements and medications during the last seven days was recorded in a face-to-face interview in 2009. Participants were asked to bring all packages of ingested preparations to the study center. Not only vitamin/mineral supplements, but also non-vitamin non-mineral non-herbal supplements and drugs containing vitamins and minerals were coded as DS.

Results

The age-standardized prevalence of DS intake was 54.3% in women and 33.8% in men, respectively. The most commonly supplemented mineral and vitamin, respectively, was magnesium (31.9%) and vitamin D (21.5%) in women and magnesium (18.0%) and vitamin E (12.0%) in men. The highest intakes, compared to the German Dietary Reference Intakes, were reported for biotin, vitamin B₆ and B₁. Excessive intakes (equal or above the European Tolerable Upper Intake Levels (UL)) were observed especially for magnesium and vitamin E. 20.2% of the women and 32.5% of the men who took magnesium supplements regularly exceeded the UL for magnesium. In case of vitamin E this was true for 8.0% of the women and 13.6% of the men. Determinants of DS use were sex, education, smoking, physical activity, neurological diseases, and stroke.

Conclusion

A high proportion of the general population aged 65 years and older in Southern Germany uses DS, especially supplements containing vitamins/minerals. The supplementation of vitamin D can be regarded as favorable in this age group, whereas the excessive intakes of vitamin E might be a cause of concern.     

Bone mineral density in a cohort of adolescents during use of norethisterone enanthate, depot-medroxyprogesterone acetate or combined oral contraceptives and after discontinuation of norethisterone enanthate

Background

Depot medroxyprogesterone acetate (DMPA), norethisterone enanthate (NET-EN) and combined oral contraceptives (COCs) have been shown to have a negative effect on bone mineral density (BMD) in adolescents. The aim of this study was to investigate BMD in 15- to 19-year-old new users of DMPA, NET-EN and COCs.

Study Design

This 5-year longitudinal study followed up new users of DMPA (n=115), NET-EN (n=115) and COCs (n=116) and 144 nonuser controls. BMD was measured at the distal radius using dual-energy X-ray absorptiometry.

Results

BMD increased in all groups (annual percent increase: nonusers, 1.49%; DMPA, 1.39%; NET-EN, 1.03%; COCs, 0.84%) during follow-up (p<.001). There was evidence for lower BMD increases per annum in NET-EN (p=.050) and COC (p=.010) users compared to nonusers but no difference between DMPA and nonusers (p=.76). In 14 NET-EN discontinuers, an overall reduction of 0.61% per year BMD was followed upon cessation by an increase of 0.69% per year (p=.066).

Conclusion

This study suggests that BMD increases in adolescents may be less in NET-EN and COC users; however, recovery of BMD in NET-EN users was found in the small sample of adolescents followed post-discontinuation.     

Vitamin D, obesity, and obesity-related chronic disease among ethnic minorities: a systematic review

Objective

To assess the association between 25-hydroxyvitamin D (25[OH]D) status and obesity, cardiovascular diseases (CVDs), the metabolic syndrome, and type 2 diabetes mellitus (T2DM) in ethnic minorities.

Methods

Databases searched were CINHAL with full text, Global Health, MEDLINE with full text, and PsycINFO from 1980 through 2010 (February). Studies were included if they 1) targeted immigrants from low- to high-income countries or ethnic minorities, 2) focused primarily on 25(OH)D and its relation to obesity, T2DM, and/or CVDs, and 3) were published in peer-reviewed journals. The influences of key confounders such as age, gender, and ethnicity on any observed relations were also assessed. Due to the heterogeneity of study characteristics, only a narrative synthesis was undertaken.

Results

Ethnic minorities had significantly higher rates of vitamin D insufficiency (25[OH]D <50 nmol/L; children 43.6-48.7% versus 10%; adults 30.3-53% versus 13.7-26%) than their white counterparts. None of the studies reported a prevalence of obesity stratified by ethnicity. There was evidence supporting links between vitamin D deficiency and obesity-related chronic diseases, with 14 of 14 studies reporting a statistically significant result with a measurement of obesity, four of five for T2DM, four of five for CVDs, and one of one for the metabolic syndrome. However, the strength of the association varied across ethnic groups depending on the index used to measure adiposity, T2DM, and CVDs. Because most of the included studies were cross-sectional and there were variations in outcome measurements, it was not possible to determine the relative contributions of obesity or vitamin D insufficiency to CVD risk and risk of T2DM or which is the initial driver It is possible both have a role to play.

Conclusion

Further research specific to migrant populations using randomized controlled trials are required to establish whether causal links between 25(OH)D and obesity-related chronic disease exist, and whether vitamin D supplementation could be valuable in the prevention or treatment of obesity-related diseases.     

Dietary intake in Head Start vs non-Head Start preschool-aged children: results from the 1999-2004 National Health and Nutrition Examination Survey

Objective

To determine whether dietary intakes of children enrolled in Head Start programs differ from those of children not attending preschool or children in non–Head Start programs.

Design

Using data from the 1999-2004 National Health and Nutrition Examination Survey, low-income, 3- to 5-year-old children were categorized into one of four preschool groups: Head Start (n=184), non–Head Start (n=189), past preschool (n=193), and no preschool (n=384). Total nutrient intakes were calculated using 24-hour parental recalls.

Statistical analyses performed

Mean macronutrient and micronutrient intakes were compared across groups and the percentage of children not meeting Recommended Dietary Allowances (RDAs) were calculated. Multivariate logistic regression was used to evaluate the relationship between preschool group and likelihood of not meeting dietary guidelines.

Results

Many children did not meet the RDA for folate (20.5%), vitamin A (39.7%), vitamin E (79.7%), calcium (40.2%), iron (28.8%), and potassium (90.8%). Compared with the other preschool groups, Head Start children had lower mean protein, saturated fat, riboflavin, calcium, and phosphorous intakes. The greatest differences in intake were observed between Head Start participants and no-preschool children. Multivariate analyses demonstrated an association between Head Start and inadequate intake of protein, thiamin, riboflavin, niacin, calcium, and selenium.

Conclusions

Compared with other low-income children, those in Head Start programs appear to be at greater risk for not meeting the RDA for several key vitamins and minerals. These differences in diet quality may present an opportunity for Head Start programs to enhance nutrition in this student population.     

Effect of vitamin A, vitamin A plus iron and multiple micronutrient-fortified seasoning powder on infectious morbidity of preschool children

Objective

Improvement of hemoglobin and serum retinol and facilitation of the mobilization of iron storage were achieved with a multiple-micronutrient-fortified diet in preschoolers for 6 mo in a suburb of Chongqing, China. We investigated whether fortification with multiple micronutrients in a diet for preschool children results in changes in children's infectious morbidity compared with diets fortified solely with vitamin A and with vitamin A plus iron.

Methods

From December 2005 to June 2006, 226 2- to 6-y-old preschool children were recruited from three nurseries randomly assigned to three different fortified-diet groups for 6 mo. Group I was fortified with vitamin A; groups II and III were fortified with vitamin A plus iron and vitamin A plus iron, thiamine, riboflavin, folic acid, niacinamide, zinc, and calcium, respectively. The secondary functional outcomes, morbidity of diarrhea and respiratory infection, were collected during supplementation.

Results

The groups were comparable concerning compliance and loss to follow-up. There was evidence of a lower incidence rate of respiratory-related illnesses, diarrhea-related illness, fewer symptoms of runny nose, cough, and fever, and shorter duration of respiratory-related illnesses and cough for children in group III compared with children in groups I and II. However, there was no significantly or clinically important difference between children in groups I and II.

Conclusion

The beneficial effects on infectious morbidity over 6 mo, in addition to some biochemical improvements, highlight the potential of this micronutrient-fortified seasoning powder supplied in a diet for preschool children.     

Effects of vitamin A deficiency on mucosal immunity and response to intestinal infection in rats

Objective

Vitamin A deficiency is associated with an increased incidence of infectious respiratory and alimentary tract diseases in children, and vitamin A supplementation can prevent and assist in treating these diseases. To clarify the mechanisms of these associations, we investigated the effects of vitamin A deficiency on mucosal immunity to intestinal infection in rats.

Methods

Specific pathogen-free Sprague-Dawley rats received a vitamin A-free diet, with (n = 20) or without (n = 20) vitamin A supplementation. Intestinal infection was induced by oral inoculation of salmonella in 10 rats in each group. The rats were killed 3 d after infection was induced, and we measured the number, maturation, and activation of dendritic cells; the expression of Toll-like receptors 2 and 4; mRNA level of myeloid differentiation primary response gene (88) (MyD88, pattern-recognition receptors and their adapter protein); immune cytokine production in the intestinal mucosa; and the amount of secretory immunoglobulin A in the gut.

Results

In vitamin-A deficient rats, the number of mucosal dendritic cells and the production of IL-12 markedly increased; the mucosal expressions of Toll-like receptor 2 and MyD88 were up-regulated, and secretions of interferon-γ and secretory immunoglobulin A were decreased. Infection aggravated the damage to the intestinal mucosa and lowered immunity in vitamin-A deficient rats.

Conclusion

Vitamin A deficiency damaged both humoral and cellular immunity in the mucosa. Modulation of dendritic cells is likely an important mechanism through which vitamin A deficiency affects mucosal immune responses against infection.     

Interrelationships of Added Sugars Intake, Socioeconomic Status, and Race/Ethnicity in Adults in the United States: National Health Interview Survey, 2005

Background

The consumption of added sugars (eg, white sugar, brown sugar, and high-fructose corn syrup) displaces nutrient-dense foods in the diet. The intake of added sugars in the United States is excessive. Little is known about the predictors of added sugar intake.

Objective

To examine the independent relationships of socioeconomic status and race/ethnicity with added sugar intake, and to evaluate the consistency of relationships using a short instrument to those from a different survey using more precise dietary assessment.

Design

Cross-sectional, nationally representative, interviewer-administered survey.

Subjects/setting

Adults (aged ≥18 years) participating in the 2005 US National Health Interview Survey Cancer Control Supplement responding to four added sugars questions (n=28,948).

Statistical analyses performed

The intake of added sugars was estimated using validated scoring algorithms. Multivariate analysis incorporating sample weights and design effects was conducted. Least squares means and confidence intervals, and significance tests using Wald F statistics are presented. Analyses were stratified by sex and controlled for potential confounders.

Results

The intake of added sugars was higher among men than women and inversely related to age, educational status, and family income. Asian Americans had the lowest intake and Hispanics the next lowest intake. Among men, African Americans had the highest intake, although whites and American Indians/Alaskan Natives also had high intakes. Among women, African Americans and American Indians/Alaskan Natives had the highest intakes. Intake of added sugars was inversely related to educational attainment in whites, African Americans, Hispanic men, and American Indians/Alaskan Native men, but was unrelated in Asian Americans. These findings were generally consistent with relationships in National Health and Nutrition Examination Survey 2003-2004 (using one or two 24-hour dietary recalls).

Conclusions

Race/ethnicity, family income, and educational status are independently associated with intake of added sugars. Groups with low income and education are particularly vulnerable to diets with high added sugars. Differences among race/ethnicity groups suggest that interventions to reduce intake of added sugars should be tailored. The National Health Interview Survey added sugars questions with accompanying scoring algorithms appear to provide an affordable and useful means of assessing relationships between various factors and added sugars intake.     

Supplement use,other dietary and demographic variables,and serum vitamin C in NHANES II.

Our objective was to evaluate the effect of regular use of nutritional supplements on serum vitamin C levels in a multivariable regression model, taking into account other dietary and demographic variables which may affect nutritional status.

We analyzed NHANES II data for subjects age 3 to 74. Analysis was limited to regular supplement users and nonusers, excluding irregular users. Multivariable regression analysis was performed with SUDAAN, incorporating sample weights and accounting for the complex survey design.

Regular supplement users had substantially higher serum vitamin C levels than nonusers (p < 0.001). The magnitude of the effect of supplement use on serum vitamin C was 0.23-0.33 mg/dL in children and teens, and 0.36-0.46 mg/dL in adults. In adults who smoked, bottom quartile vitamin C levels were 0.3 mg/dL in men and 0.4 mg/dL in women who did not use supplements, compared to 0.9 and 1.1 mg/dL in regular supplement users. There was a significant interaction of smoking and supplement use in men (p < 0.001).

Regular supplement use has a strong impact on serum vitamin C levels, independent of other dietary and demographic characteristics of supplement users which may favor improved nutritional status.     

北京市成年人膳食及营养补充剂中维生素和矿物质的摄入状况

目的研究膳食营养补充剂对北京市居民维生素和矿物质摄入水平及营养素摄入的影响。方法采用多阶段整群抽样法,抽取北京市6区县1440户家庭,调查18岁及以上成年人3992人。结果男性由膳食提供的维生素和矿物质的平均摄入量均高于女性,但是女性烟酸、维生素C的总摄入量高于男性。使用者的维生素和矿物质的摄入量均高于非使用者,在使用者中,补充剂中硫胺素的贡献率男性为60%,女性为70%,核黄素的贡献率为男性47%,女性45%,钙的贡献率为男性42%,女性为45%。使用者中维生素和矿物质达到或超过参考值的比例明显高于非使用者,特别是维生素C和钙,高出20～30个百分点。结论使用营养补充剂提高了维生素和矿物质的摄入水平,使人群达到参考摄入量的比例增加。今后营养调查中应增加营养补充剂调查,以提高营养素评价的准确度。