Urinary excretion of vitamin B12 depends on urine volume in Japanese female university students and elderly

Recent studies have shown that urinary excretion of water-soluble vitamins reflects their intake in humans. However, some have reported that physical characteristics and urine volume may affect the amount of vitamin compounds found in urine. We hypothesized that physical characteristics and urine volume could affect urinary excretion of B-group vitamins. Twenty-four–hour urine samples were collected from 186 free-living Japanese women aged 19 to 21 years and 104 free-living Japanese subjects aged 70 to 84 years. Correlations between urinary output of each B-group vitamin and body height, body weight, body mass index, body surface area, urine volume, and urinary creatinine were determined. Only urinary vitamin B₁₂ was strongly correlated to urine volume in young (r = 0.683, P < .001) and elderly (r = 0.523, P < .001) subjects. To confirm this finding, 20 Japanese adults were orally administered 1.5 mg of cyanocobalamin (500-fold higher daily intake); and correlations between urinary vitamin B₁₂ and urine volume were determined. The load of cyanocobalamin increased vitamin B₁₂ content in the urine by only 1.3-fold. Urinary vitamin B₁₂ was strongly correlated with urine volume on the day before taking, the day of taking, and the day after taking cyanocobalamin (r = 0.745, P < .001; r = 0.897, P < .0001; and r = 0.855, P < .0001, respectively). We conclude that urinary excretion of vitamin B₁₂ is dependent upon urine volume, but not on intake of vitamin B₁₂. Physical characteristics and urine volume are less important for B-group vitamins except for vitamin B₁₂ as biomarker.     

Relative and biomarker-based validity of a food frequency questionnaire that measures the intakes of vitamin B12, folate, iron, and zinc in young women

Folate, vitamin B₁₂, iron, and zinc are particularly important nutrients for women of childbearing age. We tested the hypothesis that an electronic, 235-item, semiquantitative food frequency questionnaire (FFQ) is a valid measure of dietary intake when compared with repeat dietary 24-hour recalls. Biomarkers of folate, vitamin B₁₂, iron, and zinc were determined because their measurement errors are unrelated to errors in dietary questionnaires. Female adults (N = 256) aged 18 to 35 years completed the FFQ, and a representative subset (n = 53) completed repeat dietary 24-hour recalls. The FFQ estimates (mean ± SD) were 315 ± 132 μg for folate, 3.1 ± 2.1 μg for vitamin B₁₂, 15.4 ± 5.6 mg for iron, and 15.1 ± 6.4 mg for zinc. The percentage of women classified within the same ±1 quartile for energy intake by the 2 methods was 77.3%. There was moderate agreement between the 2 dietary methods, and no systematic bias was noted for energy, folate, vitamin B₁₂, and zinc. The deattenuated energy-adjusted correlation coefficients ranged from 0.41 (dietary folate equivalents) to 0.60 (folate). Significant correlations between biomarker and nutrient intakes were found for folate (r = 0.37, P < .01) and vitamin B₁₂ (r = 0.27, P < .01). The electronic FFQ developed in the present study is a relatively valid tool that was able to adequately assess and rank individuals according to their nutrient intakes.     

Low intake of vitamin B6 is associated with irritable bowel syndrome symptoms

Most subjects with irritable bowel syndrome (IBS) experience an association between symptoms and food consumption. Although dietary intake has been the focus of previous research, attention to specific nutrients has been rare. We hypothesized that there is an association between the severity of IBS symptoms and the intake of specific food groups and specific nutrients. In this cross-sectional study, 17 human subjects with IBS, as defined according to the Rome II criteria, were recruited. IBS symptoms were recorded on diary cards every evening for 7 days, and an IBS sum score was calculated (range, 0-15). Intake of food was assessed from a food diary kept by the subjects in the same period. Associations between IBS sum score and dietary intake were explored. The daily IBS sum score was 6.43 (range, 3.86- 9.09). Intake of vitamin B₆ was the only component of the diet that was significantly associated with the IBS sum score. The median daily intake of vitamin B₆ was 0.9 mg/day (range, 0.6-1.5), the recommended daily intake for men and women is 1.6 mg/day or more and 1.2 mg/day or more, respectively. A high symptom score was associated with low vitamin B₆ intake (adjusted R² = 0.583; β = −4.431; 95% confidence interval, −6.386 to −2.476; P = 0.0002). A significant inverse association between intake of vitamin B₆ and severity of IBS symptoms might have clinical implications.     

Urinary water-soluble vitamins and their metabolite contents as nutritional markers for evaluating vitamin intakes in young Japanese women

Little information is available to estimate water-soluble vitamin intakes from urinary vitamins and their metabolite contents as possible nutritional markers. Determination of the relationships between the oral dose and urinary excretion of water-soluble vitamins in human subjects contributes to finding valid nutrition markers of water-soluble vitamin intakes. Six female Japanese college students were given a standard Japanese diet in the first week, the same diet with a synthesized water-soluble vitamin mixture as a diet with approximately onefold vitamin mixture based on Dietary Reference Intakes (DRIs) for Japanese in the second week, with a threefold vitamin mixture in the third week, and a sixfold mixture in the fourth week. Water-soluble vitamins and their metabolites were measured in the 24-h urine collected each week. All urinary vitamins and their metabolite levels except vitamin B(12) increased linearly in a dose-dependent manner, and highly correlated with vitamin intake (r=0.959 for vitamin B(1), r=0.927 for vitamin B(2), r=0.965 for vitamin B(6), r=0.957 for niacin, r=0.934 for pantothenic acid, r=0.907 for folic acid, r=0.962 for biotin, and r=0.952 for vitamin C). These results suggest that measuring urinary water-soluble vitamins and their metabolite levels can be used as good nutritional markers for assessing vitamin intakes.     

The development and evaluation of a food frequency questionnaire used in assessing vitamin D intake in a sample of healthy young Canadian adults of diverse ancestry

Little data exist on vitamin D deficiency related with intake, especially for the Canadian population. The purpose of this study was to develop and evaluate a food frequency questionnaire (FFQ) with 37 items for rapid assessment of vitamin D intake in healthy young adults of diverse ancestry. We recruited 107 subjects in Southern Ontario during the late winter of 2007 who completed an FFQ twice (FFQ-1 and FFQ-2, repeated for reproducibility assessment) and a 7-day food diary (for validation). Serum 25-hydroxyvitamin D (25(OH)D), the major biomarker of vitamin D nutritional status, and skin melanin were determined. The FFQ results were highly correlated with 7-day diary results and with serum 25(OH)D concentrations (r = 0.529, P < .001; r = 0.481, P < .001, respectively). Modifications to the FFQ, by redefining the large serving size and excluding the fortified orange juice category, improved the validity of the FFQ (r = 0.602, P < .001; r = 0.520, P < .001, respectively). The FFQ results were highly correlated (r = 0.663, P < .001), but the mean intakes were different (P < .05). Using results from a modified version of FFQ-1, we examined dietary intakes in 3 predominant groups: East Asian (n = 27), European (n = 31), and South Asian (n = 32). The European group had higher total vitamin D intake (P < .05) and the highest serum 25(OH)D concentrations (P < .05), with a trend for dairy products being responsible for this (P < .10). Because Canadians are reliant on dietary intakes of vitamin D in the wintertime, especially those with higher skin melanin, our FFQ can monitor and provide information on intake and food group consumption.     

Nutritional supplementation of hop rho iso-alpha acids, berberine, vitamin D3, and vitamin K1 produces a favorable bone biomarker profile supporting healthy bone metabolism in postmenopausal women with metabolic syndrome

Metabolic syndrome poses additional risk for postmenopausal women who are already at risk for osteoporosis. We hypothesized that a nutritional supplement containing anti-inflammatory phytochemicals and essential bone nutrients would produce a favorable bone biomarker profile in postmenopausal women with metabolic syndrome. In this 14-week, randomized trial, 51 women were instructed to consume a modified Mediterranean-style, low-glycemic-load diet and to engage in aerobic exercise. Those in the intervention arm (n = 25) additionally received 200 mg hop rho iso-alpha acids, 100 mg berberine sulfate trihydrate, 500 IU vitamin D₃, and 500 μg vitamin K₁ twice daily. Forty-five women completed the study. Baseline nutrient intake did not differ between arms. Compared with baseline, the intervention arm exhibited an approximate 25% mean decrease (P < .001) in serum osteocalcin (indicative of bone turnover), whereas the placebo arm exhibited a 21% increase (P = .003). Serum 25-hydroxyvitamin D increased 23% (P = .001) in the intervention arm and decreased 12% (P = .03) in the placebo arm. The between-arm differences for osteocalcin and 25-hydroxyvitamin D were statistically significant. Serum insulin-like growth factor I was statistically increased in both arms, but the between-arm differences were not statistically significant. Subanalysis showed that among those in the highest tertile of baseline insulin-like growth factor I, the intervention arm exhibited a significant increase in amino-terminal propeptide of type I collagen, whereas the placebo arm showed a significant decrease at 14 weeks. Treatment with rho iso-alpha acids, berberine, vitamin D₃, and vitamin K₁ produced a more favorable bone biomarker profile indicative of healthy bone metabolism in postmenopausal women with metabolic syndrome.     

Correlation of erythrocyte fatty acid composition and dietary intakes with markers of atherosclerosis in patients with myocardial infarction

The purpose of this study was to examine the hypothesis that erythrocytes that are low in n-3 fatty acids and high in trans-fatty acids and nutrient intakes are associated with the risk of atherosclerosis. Fifty patients with acute nonfatal myocardial infarction were recruited to measure their dietary intake, erythrocyte fatty acid composition, intima medial thickness (IMT), and the Gensini score, which are markers of atherosclerosis. Trans-oleic acid of erythrocytes was positively (P = .05) correlated with the carotid IMT. After adjusting for age, sex, and energy intake, the IMT was negatively associated with the intake of protein, fat, phosphate, zinc, vitamin B₁, vitamin B₂, vitamin B₆, niacin, linoleic acid, linolenic acid, total fatty acids, total n-3 fatty acids, and total n-6 fatty acids. The Gensini score was also negatively associated with the intake of protein, fat, phosphate, sodium, zinc, vitamin E, vitamin B₁, vitamin B₂, vitamin B₆, niacin, linolenic acid, total fatty acids, and total n-3 fatty acids. In conclusion, lower levels of trans-oleic acid (elaidic acid) in erythrocytes and higher intakes of vitamins, minerals, and n-3 fatty acids were associated with the decreased risk of atherosclerosis. However, these findings need further investigation in randomized controlled clinical trials before public health recommendations for atherosclerosis prevention can be made.     

Antioxidant Vitamins Intake,Ataxia Telangiectasia Mutated (ATM) Genetic Polymorphisms,and Breast Cancer Risk

Ataxia telangiectasia mutated (ATM) cells exist under a constant state of oxidative stress with high levels of reactive oxygen species, which are removed by cellular antioxidant vitamins. We investigated the independent and combined effect of antioxidant vitamins intake and the ATM genotype or diplotype on the breast cancer risk. Analyses included 323 cases and age-matched controls who participated in the Korean Breast Cancer Study during 2001–2003 with complete dietary information. The vitamin A (P < 0.01) and α-tocopherol (P < 0.01) were associated with lower breast cancer risk as well as some water-soluble vitamins including vitamin B₂ (P = 0.01), vitamin C (P < 0.01), and folic acid (P = 0.02) intake. No five single nucleotide polymorphisms (ATM-5144A > T (rs228589), IVS21 + 1049T > C (rs664677), IVS33-55T > C (rs664982), IVS34+60G > A (rs664143), and 3393T > G (rs4585)) studied showed significant differences in their allele frequencies between the cases and controls. On the other hand, compared with the diploid of ATTGT/ATTGT, as the number of ATTGT haplotype decreased, the risk of breast cancer increased (P = 0.04). The association between ATM diplotype and the breast cancer risk was predominantly among women with low intake of antioxidant vitamins including vitamin A, vitamin C, and folic acid. This study suggested that some antioxidant vitamins intake may modify the effect of ATM diplotype on the breast cancer risk among Korean women.     

Diet and nutrients are contributing factors that influence blood cadmium levels

Studies suggested the intake of Cd from diet can be approximately equivalent to that from smoking. Moreover, a mutual metabolic influence between Cd and nutrients has been reported. The purpose of this study was to evaluate the relationship between blood cadmium concentration (BCdC) and food consumption, nutrients intake (Ca, Fe, Zn, vitamin C, and vitamin D), tobacco smoking, and some other variables (age, body mass index, and residence) in 243 adults living in the Italian island of Sardinia (Sassari Province). Specifically, we hypothesized that offal consumption contributes to Cd intakes and blood levels. The BCdC was quantified by graphite furnace atomic absorption spectrometry, and information on personal data was collected through questionnaires. Smoke significantly contributed to the BCdC (P < .001). Nonsmoker subjects who eat offal showed significantly higher BCdC (P = .04). Moreover, slightly higher BCdCs were also observed in nonsmoker subjects who eat rice, fish, and bread. The BCdC positively correlated with age of subjects (r = 0.144; P = .025) and offal daily intake in nonsmokers (r = 0.393; P < .001). The intake of Ca was negatively correlated (r = −0.281; P = .001) with the BCdC in females. The multiple linear regression analysis showed smoking > consumption of offal > body mass index ≈ age as the most important risk factors for the BCdC in the selected population.     

Dietary source of vitamin B12 intake and vitamin B12 status in female elderly Koreans aged 85 and older living in rural area

Recently, we found and analyzed vitamin B₁₂ in some Korean traditional plant foods which had not reported, yet. This study was to investigate vitamin B₁₂ intake and its dietary sources and the vitamin B₁₂ status in the very old elderly Koreans. We measured serum vitamin B₁₂ level and estimated the amounts of vitamin B₁₂ intake from different dietary sources in female elderly Koreans aged 85 and over who had consumed a relatively low animal traditional diet for the whole life. The average age of the subjects (n = 127) was 98.0 years (85-108 years). The assessment on energy and nutrient intake involved a one-day 24-hour recall, and serum vitamin B₁₂ concentration was measured by radioimmunoassay. Overall diet pattern was not different between the 85-99 yr-old group and centenarians, except centenarians were taking more dairy product. The average ratio of plant food to animal food consumption was 87.5:12.5 in weight. The average vitamin B₁₂ intake of our subjects was 3.2 µg/day, and 52.7% of subjects consumed under estimated average requirement, 2.0 µg/day. On dietary source, 67.3% of dietary vitamin B₁₂ was from meat, eggs and fishes and 30.6% was from plant foods, such as soybean-fermented foods, seaweeds, and kimchi. The average serum vitamin B₁₂ concentration was 450.5 pg/mL, and low serum vitamin B₁₂ (< 200 pg/mL) was found in 9.6% of subjects. Dietary vitamin B₁₂ intake was significantly lower in subjects with low serum vitamin B₁₂ (0.79 µg/day) than those with normal serum vitamin B₁₂ (3.47 µg/day). There were no significant difference in vitamin B₁₂ intake and its dietary sources and serum vitamin B₁₂ level between the 85-99 yr-old group and centenarians. In conclusion, several plant-origin foods including seaweed, soybean-fermented foods, and kimchi, may contribute significantly to good vitamin B₁₂ status in very old elderly Koreans.     

Dietary intervention with emphasis on folate intake reduces serum lipids but not plasma homocysteine levels in hyperlipidemic patients

Hyperlipidemia and hyperhomocysteinemia are regarded as major risk factors for cardiovascular disease. Medical nutrition therapy (MNT), which involves a combination of nutritional diagnosis, therapy, and counseling for at-risk patients, has been proposed as a protocol to control these risk factors. The purpose of this study was to investigate the effect of an intensive MNT, specifically tailored to Korean hyperlipidemic patients, on levels of serum lipids and plasma homocysteine. Forty hyperlipidemic patients with blood levels of total cholesterol ≥200 mg/dL or triacylglycerol ≥150 mg/dL were recruited from the Kyung Hee University Medical Center (Seoul, Korea). They were randomly divided into control (no treatment) or experimental (MNT treatment) groups. A registered dietitian performed MNT, emphasizing dietary folate intake based on the guidelines for Korean hyperlipidemic patients; this was performed 5 times during the 12 weeks of the experiment. After the MNT period, we observed that body mass index (P < .001) and fat percentage (P < .05) was significantly decreased in the experimental group but not in the control group. Daily energy consumption, as well as carbohydrate, fat, and cholesterol intakes, all decreased significantly (P < .05) in the MNT group, whereas folate intake increased (P < .05). Blood levels of triacylglycerol (−30.8%), total cholesterol (−20.9%), low-density lipoprotein cholesterol (−14.5%), and ratio of low-density lipoprotein/high-density lipoprotein (−17.1%) were significantly lower in the experimental group after MNT (P < .001) compared with the control group. Plasma homocysteine levels were unchanged (P = .98); however, the levels of folate (P < .01), vitamin B₆ (P < .01), and vitamin B₁₂ (P < .05) increased significantly in the experimental group. These results indicate that MNT, with an emphasis on folate intake, can be effective at reducing blood levels of lipids and improving the blood levels of folate, vitamin B₆, and vitamin B₁₂ in Korean hyperlipidemic patients.     

Intakes of vegetables and related nutrients such as vitamin B complex, potassium, and calcium, are negatively correlated with risk of stroke in Korea

Consumption of vegetables and fruits is associated with a reduced risk of stroke, but it is unclear whether their protective effects are due to antioxidant vitamins or folate and metabolically related B vitamins. The purpose of the study was to test the hypothesis that intake of fruits and vegetables, which are major sources of antioxidant and vitamin B complex vitamins, reduces the risk of stroke. Cases consisted of patients diagnosed with first event of stroke (n = 69). Controls (n = 69) were age-, sex-, and body mass index-matched to cases. Multivariable-adjusted regression analysis showed that subjects who ate four to six servings of vegetable per day had a 32% reduction in the risk of stroke, and those with more than six servings per day had a reduction of 69% after adjusting for age, sex, BMI, and family history of stroke. Intakes of total fat, plant fat, calcium, potassium, vitamin B₁, vitamin B₂, vitamin B₆, niacin, and folate were significantly and negatively associated with the risk of stroke. Although the trend was not significant, stroke risk was reduced in the second quartile (1.21-2.66 servings per week) of fish intake. However, intake of fruits (average daily intake of 1.0 serving) and antioxidant vitamins such as carotene, vitamin C, and vitamin E was not associated with the risk of stroke. In conclusion, our observational study suggests that intake of fat and vegetables, rich sources of vitamin B complex, calcium, and potassium may protect against stroke.     

Folic acid and vitamin B12 supplementation lowers plasma homocysteine but has no effect on serum bone turnover markers in elderly women: a randomized,double-blind,placebo-controlled trial

An elevated homocysteine level is a newly recognized risk factor for osteoporosis. Older individuals may have elevated homocysteine levels due to inadequate folate intake and/or lower absorption of vitamin B₁₂. The aim of this study was to determine whether there is an impact of folic acid and vitamin B₁₂ supplementation on homocysteine levels and, subsequently, on bone turnover markers in older women with mildly to moderately elevated homocysteine levels. It is hypothesized that supplementation with folic acid and vitamin B₁₂ will improve homocysteine levels and, in turn, positively modify bone turnover markers in this population. This randomized, double-blind, placebo-controlled trial included 31 women (65 to 93 years) with homocysteine levels greater than 10 μmol/L. Participants were randomly assigned to receive either a daily folic acid (800 μg) and vitamin B₁₂ (1000 μg) (n = 17) or a matching placebo (n = 14) for 4 months. The results showed significantly lower homocysteine concentrations in the vitamin group compared to the placebo group (10.6 vs 18.5 μmol/L, P = .007). No significant difference in serum alkaline phosphatase or C-terminal cross-linking telopeptide of type I collagen was found between the vitamin and placebo groups before or after supplementation. The use of folic acid and vitamin B₁₂ as a dietary supplement to improve homocysteine levels could be beneficial for older women, but additional research must be conducted in a larger population and for a longer period to determine if there is an impact of supplementation on bone turnover markers or other indicators of bone health.     

Intake of vitamins B1, B2, C, A and E estimated on the basis of analysis of weekly diets of 19 Finnish hospitals

Contents of vitamins B₁, B₂, C, A and E were determined and intakes of these vitamins calculated in homogenized weekly diets collected from 19 central hospitals throughout Finland. In addition, the possibility of using the hospital diet data to estimate the level of average daily vitamin intake in Finland was evaluated. This was facilitated by comparing the daily food consumption in hospitals with the average daily food consumption in Finland and assessing the average vitamin intake of Finnish people accordingly. Intakes of vitamins A, B₂;and C (1600 RE, 2.9 mg and 148.9 mg day^?1, respectively) exceeded the recommendations for hospital diets. On the other hand, mean intakes of vitamins E and B₁(8.9 and 1.0 mg day^?1, respectively) were slightly below the recommendations. Comparison of daily food consumption from hospital diets with the average daily food consumption in Finland suggests that average Finnish intakes of vitamins B₁and E are close to the intake values obtained from the hospital diets studied.     

Plasma 25-hydroxyvitamin D is positively associated with folate and vitamin B12 levels in adolescents

Vitamin D affects the absorption of folate in vitro, and perhaps of vitamin B₁₂ (B₁₂). However, epidemiological studies on the association of vitamin D with folate and B₁₂ are inconclusive. We hypothesized a positive association of plasma 25-hydroxyvitamin D [25(OH)D] with folate and B₁₂ levels in adolescents. This hypothesis was tested in a cross-sectional study of healthy adolescents (11–16 years old; n = 1416), selected from public middle schools from across Kuwait, using stratified multistage cluster random sampling. Plasma 25(OH)D was measured by LC–MS/MS. Serum B₁₂ and total folate in hemolyzed whole blood were analyzed with commercial kits; RBC and plasma folate were calculated from total folate. Data on potential confounders were collected from the parents and adolescents. In a univariable model, 25(OH)D as a continuous variable was positively associated with each of total, RBC, and plasma folate (P < .001). After adjusting for potential confounders, this association remained significant with total folate (β = 2.0, P < .001) and red blood cell folate (β = 1.8, P < .001), but not with plasma folate (β = 0.2, P = .34). A similar pattern of association was evident when 25(OH)D was fitted as categorical variable. Correlation between B₁₂ and 25(OH)D was weak but significant (ρ = 0.1, P < .001). 25(OH)D was positively associated with B₁₂ in both univariable and multivariable models (P < .001) when fitted as a categorical variable only. Simultaneous quantile regression confirmed these results. We conclude that plasma 25(OH)D is positively associated with folate and B₁₂ levels in adolescents. Properly designed large-scale randomized controlled trials are warranted to investigate the causal role of vitamin D in folate and B₁₂ absorption.     

Evaluation of vitamin B6 intake and status of 20- to 64-year-old Koreans

BACKGROUND/OBJECTIVES

Recent research regarding vitamin B₆ status including biochemical index is limited. Thus, this study estimated intakes and major food sources of vitamin B₆; determined plasma pyridoxal 5''-phosphate (PLP); and assessed vitamin B₆ status of Korean adults.

MATERIALS/METHODS

Three consecutive 24-h diet recalls and fasting blood samples were collected from healthy 20- to 64-year-old adults (n = 254) living in the Seoul metropolitan area, cities of Kwangju and Gumi, Korea. Vitamin B₆ intake and plasma PLP were analyzed by gender and by vitamin B₆ supplementation. Pearson''s correlation coefficient was used to determine associations of vitamin B₆ intake and plasma PLP.

RESULTS

The mean dietary and total (dietary plus supplemental) vitamin B₆ intake was 1.94 ± 0.64 and 2.41 ± 1.45 mg/day, respectively. Median (50th percentile) dietary intake of men and women was 2.062 and 1.706 mg/day. Foods from plant sources provided 70.61% of dietary vitamin B₆ intake. Only 6.3% of subjects consumed total vitamin B₆ less than Estimated Average Requirements. Plasma PLP concentration of all subjects was 40.03 ± 23.71 nmol/L. The concentration of users of vitamin B₆ supplements was significantly higher than that of nonusers (P < 0.001). Approximately 16% of Korean adults had PLP levels < 20 nmol/L, indicating a biochemical deficiency of vitamin B₆, while 19.7% had marginal vitamin B₆ status. Plasma PLP concentration showed positive correlation with total vitamin B₆ intake (r = 0.40984, P < 0.0001).

CONCLUSIONS

In this study, vitamin B₆ intake of Korean adults was generally adequate. However, one-third of subjects had vitamin B₆ deficiency or marginal status. Therefore, in some adults in Korea, consumption of vitamin B₆-rich food sources should be encouraged.     

Higher amounts of body fat are associated with inadequate intakes of calcium and vitamin D in African American women

Calcium and vitamin D are associated with obesity. We hypothesized that African American women with higher calcium and vitamin D intakes would have lower body fat compared with women with lower calcium and vitamin D intakes. This cross-sectional study included 100 premenopausal African American women aged 18 to 40 years with a spectrum of body mass indices (17.3-46.7 kg/m²). Dietary information was obtained using 24-h recalls. Total body fat was determined by dual-energy x-ray absorptiometry and reported as percentage body fat (%BF). Subjects' data were divided into 2 groups (n = 50 per group) based on the median quartile of %BF, and differences were determined using independent t tests. Women with at least 37.9%BF had mean calcium (mg per day ± SD) and vitamin D intakes (µg per day ± SD) of 528.6 ± 146.0 and 3.8 ± .9, respectively. In comparison, women with lower %BF (<37.9%) had higher (P < .001) calcium and vitamin D intakes of 911.5 ± 208.3 and 5.0 ± 0.8, respectively. Partial correlation coefficients (controlling for the confounding variables of fat, carbohydrate, and protein intakes) indicated significant (P < 0.001) inverse associations between calcium intake and %BF (r = −.666), and vitamin D and %BF (r = −.460) in the 100 women. In conclusion, women with lower intakes of calcium and vitamin D were more likely to exhibit excessive adiposity compared with women with higher intakes.     

Low and high homocysteine are associated with mortality independent of B group vitamins but interactive with cognitive status in a free-living elderly cohort

Hyperhomocysteinemia and cognitive impairment both predict mortality and partly because of dietary associations. We have hypothesized that for, nutritional reasons, homocysteine and cognition may act jointly to determine elder survival. In a Nutrition and Health Survey in Taiwan (1999-2000), some 1412 representative elderly were followed up for mortality up to 10 years. Cognition was assessed by the Short Portable Mental Status Questionnaire. Food and B vitamin intakes with their biomarkers, and plasma homocysteine, were measured at baseline. The possible effects of cognition on homocysteine-associated mortality were ascertained with Cox proportional-hazards models. Homocysteine was higher in those who were older, male, and single, consumed less fish and tea, and with alcohol and smoking. In models adjusted for these variables, when homocysteine exceeded 14.5 μmol/L, mortality was 1.80-fold more than when <9.3 μmol/L (hazard ratio [HR], 1.80; 95% confidence interval [95% CI], 1.20-2.71). P for trend was 0.002 and interactive with sex (P < .002). However, these homocysteine-mortality associations were dependent on cognition (P = .03); adjustment for food intake or nutrient status made little difference. Homocysteine did not predict cognitive impairment (adjusted OR, 1.40; 95% CI = 0.50-3.93). Vitamins B₁, B₂, and B₆ accounted somewhat for cognitive impairment. Cognition predicted mortality, fully adjusted for available covariates and also for homocysteine (HR, 3.66; 95% CI, 1.64-8.20) but interactively with homocysteine. Thus, the B-group vitamin insufficiency and cognitive impairment associations with premature mortality are confirmed. Yet cognition is inter-related with homocysteine in its association with survival in ways not detectably altered by foods or food-derived vitamins.     

A high-fat diet in the presence of vitamin D deficiency status is associated with a negative influence on calcaneal quantitative ultrasound parameters in young adults: a cross-sectional study

Vitamin D deficiency and a high-fat diet are considered health problems worldwide. The aims of this study were to examine the prevalence of vitamin D deficiency/insufficiency in young adults, factors related to the vitamin D status, and the influence of vitamin D deficiency and/or a high-fat diet on bone parameters. Here, we investigated the hypothesis that a high-fat diet in the presence of a vitamin D-deficient status would have a more negative influence on bone parameters than a normal-fat diet with such a status. In the present study, we targeted young Japanese adults aged 21-23 (n = 175). We conducted a diet survey based on 3-day food records, biochemical examination of serum, and quantitative ultrasound measurements at the calcaneus. As a result, the rates of vitamin D deficiency {serum 25-hydroxyvitamin D₃ [25(OH)D] concentration less than 20 ng/mL} and insufficiency [serum 25(OH)D concentration less than 30 ng/mL but not less than 20 ng/mL] were 60.6 and 30.9%, respectively. A positive correlation was observed between the serum 25(OH)D level and serum bone-specific alkaline phosphatase level, which is a serum marker of bone formation (r = 0.253, P< .01) or the speed of sound (SOS) as an index of bone density (r = 0.259, P< .01). A negative correlation was observed between the ratio of fat intake to total energy intake (%E) and serum 25(OH)D levels (r = −0.206, P< .01). Furthermore, we revealed that a high-fat diet in the presence of a vitamin D deficient status reduced the SOS parameter compared with a normal-fat diet with a vitamin D-deficient status (P< .05).     

Low energy intake and dietary quality are associated with low objective sleep quality in young Japanese women

Literature reports suggest that subjective sleep quality is associated with nutrient intake in elderly people and workers. However, few studies have suggested an association between objective sleep quality and dietary intake in adolescents and young women. We hypothesized that objective sleep quality is associated with dietary intake in adolescents and young women. We evaluated the association between energy and nutrient intake and objective sleep quality in adolescents and young Japanese women. In a cross-sectional study of 80 women aged 18-27 years, dietary intake was assessed using the self-administered diet history questionnaire. Objective sleep quality was assessed by actigraphy. Lifestyle characteristics, dietary habits, and mental health were assessed using specific questionnaires. Subjects were classified into 3 groups according to sleep efficiency (SE <80%, 80%-85%, and ≥85%), and the relationships between dietary intake and objective sleep quality were statistically evaluated. No significant differences occurred in lifestyle characteristics, physical activity levels, eating behavior, and mental health status among the 3 SE groups. Energy intake was significantly lower in the low-SE group than in the middle- (P = .004) and high- (P = .015) SE groups. Protein intake was significantly lower in the low-SE group than in the high-SE group (P = .034). The mean energy-adjusted intakes of vitamin K, vitamin B₂, potassium, magnesium, iron, zinc, copper, and tryptophan were significantly lower in the low-SE group than in the high-SE group. Adequate energy intake and a high-quality diet including vitamins, minerals, and tryptophan may result in high sleep quality and help prevent sleep problems.