Long-term supplementation with iron does not enhance growth in malnourished Bangladeshi children.
(17/2124)
To evaluate the effect of long-term oral iron supplementation on growth, 250 children aged 6-71 mo were studied in a randomized double-blind controlled trial. The intervention group received 125 mg of ferrous gluconate (15 mg elemental iron) plus multivitamins (vitamins A, D and C); the comparison group received only multivitamins daily for 12 mo. Weight (kg) and height (cm) were measured every month. Eighty three percent of the children continued the treatment for one year. The weight increment over the 12-mo period was 1.35 +/- 0.65 kg (mean +/- SD) in the intervention group and 1.39 +/- 0.54 kg in the comparison group. The height increments were 6.01 +/- 1.47 and 6.18 +/- 1.58 cm in the intervention and comparison groups, respectively. Mean weight and height increments did not differ; in an analysis stratified according to different age and nutritional categories, they also did not differ between the two groups, indicating that long-term iron supplementation does not increase growth in children. (+info)
Homocyst(e)ine and risk of cerebral infarction in a biracial population : the stroke prevention in young women study.
(18/2124)
BACKGROUND AND PURPOSE: Genetic enzyme variation and vitamin intake are important determinants of blood homocyst(e)ine levels. The prevalence of common genetic polymorphisms influencing homocyst(e)ine levels varies by race, and vitamin intake varies by socioeconomic status. Therefore, we examined the effect of vitamin intake, race, and socioeconomic status on the association of homocyst(e)ine with stroke risk. METHODS: All 59 hospitals in the greater Baltimore-Washington area participated in a population-based case-control study of stroke in young women. One hundred sixty-seven cases of first ischemic stroke among women aged 15 to 44 years were compared with 328 controls identified by random-digit dialing from the same region. Risk factor data were collected by standardized interview and nonfasting phlebotomy. Plasma homocyst(e)ine was measured by high-performance liquid chromatography and electrochemical detection. RESULTS: Blacks and whites did not differ in median homocyst(e)ine levels, nor did race modify the association between homocyst(e)ine and stroke. After adjustment for cigarettes per day, poverty status, and regular vitamin use, a plasma homocyst(e)ine level of >/=7.3 micromol/L was associated with an odds ratio for stroke of 1.6 (95% CI, 1.1 to 2.5). CONCLUSIONS: The association between elevated homocyst(e)ine and stroke was independent not only of traditional vascular risk factors but also of vitamin use and poverty status. The degree of homocyst(e)ine elevation associated with an increased stroke risk in young women is lower than that previously reported for middle-aged men and the elderly and was highly prevalent, being present in one third of the control group. (+info)
Use of dietary supplements in the United States, 1988-94.
(19/2124)
OBJECTIVES: This report presents estimates of the prevalence of use of dietary supplements among the U.S. population by various demographic and descriptive characteristics, the number of products taken, and types of supplements taken by broad product-type categories. METHODS: The third National Health and Nutrition Examination Survey (NHANES III) is a nationally representative survey of the civilian, noninstitutionalized U.S. population, 2 months of age or over. Participants were asked about their use of vitamin and/or mineral supplements in the past month. Many also reported use of other dietary supplements. RESULTS: Approximately 40 percent of the population took dietary supplements during the month prior to the interview. Females (44 percent) were more likely to take a supplement than males (35 percent). Non-Hispanic white persons (43 percent) were more likely to take supplements than non-Hispanic black persons (30 percent) and Mexican American persons (29 percent). Children 1-5 years of age were major users of supplements. Among adults 20 years of age and older, there was a trend toward increasing use of dietary supplements with age. Higher levels of education, income, and self-reported health status were all positively related to supplement use. Sixty-seven percent of supplement users took only one supplement, with the majority of them taking a combination vitamin/mineral product (46 percent). CONCLUSIONS: A substantial proportion of the U.S. population takes vitamins, minerals, and/or other dietary supplements. (+info)
Nutritional and botanical interventions to assist with the adaptation to stress.
(20/2124)
Prolonged stress, whether a result of mental/emotional upset or due to physical factors such as malnutrition, surgery, chemical exposure, excessive exercise, sleep deprivation, or a host of other environmental causes, results in predictable systemic effects. The systemic effects of stress include increased levels of stress hormones such as cortisol, a decline in certain aspects of immune system function such as natural killer cell cytotoxicity or secretory-IgA levels, and a disruption of gastrointestinal microflora balance. These systemic changes might be a substantial contributor to many of the stress-associated declines in health. Based on human and animal research, it appears a variety of nutritional and botanical substances - such as adaptogenic herbs, specific vitamins including ascorbic acid, vitamins B1 and B6, the coenzyme forms of vitamin B5 (pantethine) and B12 (methylcobalamin), the amino acid tyrosine, and other nutrients such as lipoic acid, phosphatidylserine, and plant sterol/sterolin combinations - may allow individuals to sustain an adaptive response and minimize some of the systemic effects of stress. (+info)
Maternal supplemental and dietary zinc intake and the occurrence of neural tube defects in California.
(21/2124)
The authors investigated the association between maternal preconceptional supplemental and dietary zinc intake and risk of neural tube defects (NTDs) in a population-based case-control study conducted between 1989 and 1991 in California. Cases were 430 NTD-affected fetuses/infants, and controls were 429 randomly selected non-malformed infants. Mothers reported their preconceptional use of vitamin, mineral, and food supplements, and completed a 98-item food frequency questionnaire. Increased total preconceptional zinc intake was associated with a reduced risk for NTDs (quintile 5 vs. quintile 1, odds ratio (OR) = 0.65, 95% confidence interval (CI) 0.43, 0.99). Phytate intake, a constituent of the diet known to impede zinc absorption, appeared to modify the zinc - NTD association. In addition, increased servings of animal products, the most bioavailable food source of zinc, was associated with a reduced risk for NTDs (quintile 5 vs. quintile 1, OR = 0.49, 95% CI 0.32, 0.76). Risk estimates for zinc intake were changed little after controlling for multiple sociodemographic factors and total folate intake, but were attenuated after controlling for nutrients highly correlated with dietary sources of zinc, such as protein. In sum, the analyses indicate that risk of NTDs in infants and fetuses decreased with increasing maternal preconceptional zinc intake. However, it remains unclear whether increased zinc intake, or another nutrient or combination of nutrients highly correlated with zinc intake in the diet, is causally associated with reduced NTD risk. (+info)
Antioxidant vitamins and the prevention of coronary heart disease.
(22/2124)
Clinical use of antioxidant vitamin supplementation may help to prevent coronary heart disease (CHD). Epidemiologic studies find lower CHD morbidity and mortality in persons who consume larger quantities of antioxidants in foods or supplements. Clinical trials indicate that supplementation with certain nutrients is beneficial in reducing the incidence of CHD events. Recent studies show that supplementation with antioxidant vitamins E and C have benefits in CHD prevention; however, supplementation with beta-carotene may have deleterious effects and is not recommended. Current evidence suggests that patients with CHD would probably benefit from taking vitamin E in a dosage of 400 IU per day and vitamin C in a dosage of 500 to 1,000 mg per day. Clinicians may also want to consider vitamin supplementation for CHD prevention in high-risk patients. Folate lowers elevated homocysteine levels, but evidence for routine supplemental use does not yet exist. Other nutritional supplements are currently under investigation. (+info)
Multivitamin supplementation and risk of birth defects.
(23/2124)
It is widely accepted that supplementation with folic acid, a B vitamin, reduces the risk of neural tube defects (NTDs). This case-control study tested the hypothesis that multivitamins reduce risks of selected birth defects other than NTDs. Infants with and without birth defects and aborted fetuses with birth defects were ascertained in the greater metropolitan areas of Boston, Philadelphia, and Toronto during 1993-1996. Mothers were interviewed within 6 months after delivery about a variety of factors, including details on vitamin use. Eight case groups were included: cleft lip with or without cleft palate, cleft palate only, conotruncal defects, ventricular septal defects, urinary tract defects, limb reduction defects, congenital hydrocephaly, and pyloric stenosis (n's ranged from 31 to 186). Controls were 521 infants without birth defects (nonmalformed controls) and 442 infants with defects other than those of the cases (malformed controls). Daily multivitamin supplementation was evaluated according to gestational timing categories, including periconceptional use (28 days before through 28 days after the last menstrual period). Odds ratios (ORs) below 1.0 were observed for all case groups except cardiac defects, regardless of control type. For periconceptional use, ORs with 95% confidence intervals that excluded 1.0 were estimated for limb reduction defects using both nonmalformed controls (OR = 0.3) and malformed controls (OR = 0.2) and for urinary tract defects using both nonmalformed controls (OR = 0.6) and malformed controls (OR = 0.5). Statistically significant ORs for use that began after the periconceptional period were observed for cleft palate only and urinary tract defects. These data support the hypothesis that periconceptional vitamin supplementation may extend benefits beyond a reduction in NTD risk. However, other than folic acid's protecting against NTDs, it is not clear what nutrient or combination of nutrients might affect risk of other specific defects. (+info)
Megalin knockout mice as an animal model of low molecular weight proteinuria.
(24/2124)
Megalin is an endocytic receptor expressed on the luminal surface of the renal proximal tubules. The receptor is believed to play an important role in the tubular uptake of macromolecules filtered through the glomerulus. To elucidate the role of megalin in vivo and to identify its endogenous ligands, we analyzed the proximal tubular function in mice genetically deficient for the receptor. We demonstrate that megalin-deficient mice exhibit a tubular resorption deficiency and excrete low molecular weight plasma proteins in the urine (low molecular weight proteinuria). Proteins excreted include small plasma proteins that carry lipophilic compounds including vitamin D-binding protein, retinol-binding protein, alpha(1)-microglobulin and odorant-binding protein. Megalin binds these proteins and mediates their cellular uptake. Urinary loss of carrier proteins in megalin-deficient mice results in concomitant loss of lipophilic vitamins bound to the carriers. Similar to megalin knockout mice, patients with low molecular weight proteinuria as in Fanconi syndrome are also shown to excrete vitamin/carrier complexes. Thus, these results identify a crucial role of the proximal tubule in retrieval of filtered vitamin/carrier complexes and the central role played by megalin in this process. (+info)