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Concept: Dietary mineral

190

BACKGROUND: Vitamin K2 contributes to bone and cardiovascular health. Therefore, two vitamin K2 homologues, menaquinone-4 (MK-4) and menaquinone-7 (MK-7), have been used as nutrients by the food industry and as nutritional supplements to support bone and cardiovascular health. However, little is known about the bioavailability of nutritional MK-4. To investigate MK-4 and MK-7 bioavailability, nutritional doses were administered to healthy Japanese women. FINDINGS: Single dose administration of MK-4 (420 mug; 945 nmol) or MK-7 (420 mug; 647 nmol) was given in the morning together with standardized breakfast. MK-7 was well absorbed and reached maximal serum level at 6 h after intake and was detected up to 48 h after intake. MK-4 was not detectable in the serum of all subjects at any time point. Consecutive administration of MK-4 (60 mug; 135 nmol) or MK-7 (60 mug; 92 nmol) for 7 days demonstrated that MK-4 supplementation did not increase serum MK-4 levels. However, consecutive administration of MK-7 increased serum MK-7 levels significantly in all subjects. CONCLUSIONS: We conclude that MK-4 present in food does not contribute to the vitamin K status as measured by serum vitamin K levels. MK-7, however significantly increases serum MK-7 levels and therefore may be of particular importance for extrahepatic tissues.

Concepts: Health, Nutrition, Nutrient, Vitamin, Essential nutrient, Dietary supplement, Food, Dietary mineral

173

Selenium (Se) is an essential human micronutrient with critical roles in immune functioning and antioxidant defence. Estimates of dietary Se intakes and status are scarce for Africa although crop surveys indicate deficiency is probably widespread in Malawi. Here we show that Se deficiency is likely endemic in Malawi based on the Se status of adults consuming food from contrasting soil types. These data are consistent with food balance sheets and composition tables revealing that >80% of the Malawi population is at risk of dietary Se inadequacy. Risk of dietary Se inadequacy is >60% in seven other countries in Southern Africa, and 22% across Africa as a whole. Given that most Malawi soils cannot supply sufficient Se to crops for adequate human nutrition, the cost and benefits of interventions to alleviate Se deficiency should be determined; for example, Se-enriched nitrogen fertilisers could be adopted as in Finland.

Concepts: Human, Agriculture, Nutrition, Africa, Dietary mineral, Nitrogen, Selenium, Madagascar

173

Vitamin D insufficiency in children may have long-term skeletal consequences as vitamin D affects calcium absorption, bone mineralization and bone mass attainment.

Concepts: Osteoporosis, Bone, Vitamin D, Bone density, Density, Skeletal system, Calcium, Dietary mineral

60

Dietary supplements, such as herbal or complementary nutritional products and micronutrients (vitamins and minerals), are commonly used in the United States, yet national data on adverse effects are limited.

Concepts: Nutrition, United States, Fat, Nutrient, Vitamin, Dietary mineral, Poverty in the United States, U.S. state

51

Iron, potassium, zinc, and other minerals might impact the development of premenstrual syndrome (PMS) through multiple mechanisms, but few studies have evaluated these relations. We conducted a case-control study nested within the prospective Nurses' Health Study II (1991-2001). Participants were free from PMS at baseline. After 10 years, 1,057 women were confirmed as PMS cases and 1,968 as controls. Mineral intake was assessed using food frequency questionnaires completed in 1991, 1995, and 1999. After adjustment for calcium intake and other factors, women in the highest quintile of nonheme iron intake had a relative risk of PMS of 0.64 (95% confidence interval (CI): 0.44, 0.92; P for trend = 0.04) compared with women in the lowest quintile. Women in the highest quintile of potassium intake had a relative risk of 1.46 (95% CI: 0.99, 2.15; P for trend = 0.04) compared with women in the lowest quintile. High intake of zinc from supplements was marginally associated with PMS (for intake of ≥25 mg/day vs. none, relative risk = 0.69, 95% CI: 0.46, 1.02; P for trend = 0.05). Intakes of sodium, magnesium, and manganese were unrelated to PMS risk. These findings suggest that dietary minerals may be useful in preventing PMS. Additional studies are needed to confirm these relations.

Concepts: Epidemiology, Magnesium, Calcium, Dietary mineral, Mineral, Sodium, Potassium, Dietary minerals

45

Although breakfast consumption is widely considered to be an important component of a healthy lifestyle, few UK studies have examined differences in nutrient intakes between breakfast consumers and breakfast skippers among children and adolescents. We investigated associations between breakfast skipping in 4-18-year-olds and their nutrient intakes using data from the UK’s National Diet and Nutrition Survey Rolling Programme. Dietary data were derived from 4-d estimated food diaries of 802 children aged 4-10 years and 884 children aged 11-18 years (1686 in total). Daily nutrient intakes of children with different breakfast habits were compared by one-way ANCOVA adjusting for relevant covariates (sex, age, ethnicity, equivalised household income and BMI). Within-person analysis was carried out on children with an irregular breakfast habit (n 879) comparing nutrient intakes on breakfast days with those on non-breakfast days using repeated measures ANCOVA. We observed that the overall nutritional profile of the children in terms of fibre and micronutrient intake was superior in frequent breakfast consumers (micronutrients: folate, Ca, Fe and I (P<0·01)) and, for the 4-10 years age group, on breakfast days (micronutrients: folate, vitamin C, Ca and I (P<0·01)). Also, significantly higher proportions of breakfast-consuming children met their reference nutrient intakes of folate, vitamin C, Ca, Fe and I compared with breakfast skippers (χ 2 analysis, P<0·001). Our study adds to the body of data linking breakfast consumption with higher quality dietary intake in school-age children, supporting the promotion of breakfast as an important element of a healthy dietary pattern in children.

Concepts: Nutrition, Nutrient, Vitamin, Essential nutrient, Dietary mineral, United Kingdom, Diet, Micronutrient

44

Ensuring that a woman is well-nourished, both before and during pregnancy, is crucial for the health of the woman and that of the unborn child.(1) Maternal deficiency in key nutrients has been linked to pre-eclampsia, restricted fetal growth, neural tube defects, skeletal deformity and low birth weight.(1,2) Many nutritional supplements containing vitamins, minerals and other micronutrients are heavily marketed to women for all stages of pregnancy. However, much of the evidence for vitamin supplementation in pregnancy comes from studies carried out in low-income countries,(3) where women are more likely to be undernourished or malnourished than within the UK population. The challenges lie in knowing which supplements are beneficial and in improving uptake among those at most need. Here we summarise current UK guidance for vitamin supplementation in pregnancy and review the evidence behind it.

Concepts: Nutrition, Nutrient, Vitamin, Essential nutrient, Dietary supplement, Dietary mineral, Folic acid, Malnutrition

39

Nearly half of the world’s population obtains its daily calories from rice grains, which lack or have insufficient levels of essential micronutrients. The deficiency of micronutrients vital for normal growth is a global health problem, and iron, zinc and vitamin A deficiencies are the most prevalent ones. We developed rice lines expressing Arabidopsis NICOTIANAMINE SYNTHASE 1 (AtNAS1), bean FERRITIN (PvFERRITIN), bacterial CAROTENE DESATURASE (CRTI) and maize PHYTOENE SYNTHASE (ZmPSY) in a single genetic locus in order to increase iron, zinc and β-carotene content in the rice endosperm. NAS catalyzes the synthesis of nicotianamine (NA), which is a precursor of deoxymugeneic acid (DMA) iron and zinc chelators, and also chelate iron and zinc for long distance transport. FERRITIN provides efficient storage of up to 4500 iron ions. PSY catalyzes the conversion of GGDP to phytoene, and CRTI performs the function of desaturases required for the synthesis of β-carotene from phytoene. All transgenic rice lines have significantly increased β-carotene, iron, and zinc content in the polished rice grains. Our results establish a proof-of-concept for multi-nutrient enrichment of rice grains from a single genetic locus, thus offering a sustainable and effective approach to address different micronutrient deficiencies at once.

Concepts: Gene, Genetics, Nutrition, Chromosome, Dietary mineral, Zinc, Micronutrient, Rice

28

Proper nutrition, not simply adequate energetic intake, is needed to achieve optimal dance performance. However, little scientific research exists concerning nutrition in dance, and so, to propose nutritional guidelines for this field, recommendations need to be based mainly on studies done in other physically active groups. To diminish the risk of energy imbalance and associated disorders, dancers must consume at least 30 kcal/kg fat-free mass/day, plus the training energy expenditure. For macronutrients, a daily intake of 3 to 5 g carbohydrates/kg, 1.2 to 1.7 g protein/kg, and 20 to 35% of energy intake from fat can be recommended. Dancers may be at increased risk of poor micronutrient status due to their restricted energy intake; micronutrients that deserve concern are iron, calcium, and vitamin D. During training, dancers should give special attention to fluid and carbohydrate intake in order to maintain optimal cognition, motivation, and motor skill performance. For competition/stage performance preparation, it is also important to ensure that an adequate dietary intake is being achieved. Nutritional supplements that may help in achieving specific nutritional goals when dietary intake is inadequate include multivitamins and mineral, iron, calcium, and vitamin D supplements, sports drinks, sports bars, and liquid meal supplements. Caffeine can also be used as an ergogenic aid. It is important that dancers seek dietary advice from qualified specialists, since the pressure to maintain a low body weight and low body fat levels is high, especially in styles as ballet, and this can lead to an unbalanced diet and health problems if not correctly supervised.

Concepts: Metabolism, Nutrition, Obesity, Fat, Nutrient, Vitamin, Dietary mineral, Micronutrient

28

In metabolic bone diseases, the alterations in fibrillar level bone-material quality affecting macroscopic mechanical competence are not well-understood quantitatively. Here, we quantify the fibrillar level deformation in cantilever bending in a mouse model for hereditary rickets (Hpr). Microfocus in-situ synchrotron small-angle X-ray scattering (SAXS) combined with cantilever bending was used to resolve nanoscale fibril strain in tensile- and compressive tissue regions separately, with quantitative backscattered scanning electron microscopy used to measure microscale mineralization. Tissue-level flexural moduli for Hpr mice were significantly (p<0.01) smaller compared to wild-type (~5 to 10-fold reduction). At the fibrillar level, the fibril moduli within the tensile and compressive zones were significantly (p<0.05) lower by ~3- to 5-fold in Hpr mice compared to wild-type mice. Hpr mice have a lower mineral content (24.2±2.1Cawt.% versus 27.4±3.3Ca wt.%) and its distribution was more heterogeneous compared to wild-type animals. However, the average effective fibril modulus did not differ significantly (p>0.05) over ages (4, 7 and 10weeks) between tensile and compressive zones. Our results indicate that incompletely mineralized fibrils in Hpr mice have greater deformability and lower moduli in both compression and tension, and those compressive and tensile zones have similar moduli at the fibrillar level.

Concepts: Electron, Dietary mineral, Mineral, X-ray crystallography, Scanning electron microscope, Young's modulus, X-rays, Small-angle X-ray scattering