www.nutri-facts.org

The majority of elderly people in Brazil have too low vitamin D levels

Fri, 24 May 2013 11:45:00 +0200

The observational study measured 25-hydroxyvitamin D levels during summer and winter periods in various groups of people totaling 591 participants: nursing home residents and middle-class community dwellers
(90–95% white, 5–10% black) as well as physically active elderly people and a group of young individuals, age 17–35 (60–75% white, 20% Asian and 5–12% black). The study results showed that 73% of the partici-pants had 25(OH)D concentrations below the recommended value of 75 nmol/L (1). Much lower 25(OH)D values were found in the older individuals (between 24 ng/ml in summer and 14 ng/ml in winter) as com-pared to younger individuals (between 41 ng/ml in summer and 28 ng/ml in winter).

The researchers commented that these results point to the need for public health action by the government, which could implement measures such as vitamin D supplement distribution to nursing homes, food fortifi-cation and medical education about the high prevalence of this condition among the elderly, especially about the associated higher risk of fractures. The number of individuals in the study who received vitamin D sup-plements was very low. Those who used vitamin D supplements took 200–400 IU per day, which was not enough to prevent deficiency. The Endocrine Practice Guidelines recommends adults take 1,500–2,000 IU vitamin D per day to prevent vitamin D deficiency (2).

1. Maeda S. S. et al. Factors affecting vitamin D status in different populations in the city of São Paulo, Brazil: the São PAulo vitamin D Evaluation Study (SPADES). BMC Endocrine Disorders. 2013; 13:14.

2. Holick M. F. et al. Endocrine Society: Evaluation, treatment, and prevention of vitamin D deficiency: an endocrine society clinical practice guideline. JCEM. 2011; 96(7):1911-1930.

Magnesium may be as important as calcium for children’s bone health

Wed, 22 May 2013 13:03:00 +0200

The observational study measured the absorbed amounts of calcium and magnesium from the diet (foods and beverages) as well as bone mineral content and density of 63 healthy children, four to eight years old who were not taking any multivitamins or minerals (1). The results showed that the amounts of magnesium consumed and absorbed were key predictors of how much bone children had. Dietary calcium intake, how-ever, was not significantly associated with total bone mineral content or density.

The researchers concluded that it is important for children to have a balanced, healthy diet with good sources of minerals, including both calcium and magnesium. While it is known that magnesium is important for bone health in adults, the current study has shown that magnesium intake and absorption are also related to bone mineral content in young children.

1. Abrams S. A. et al. Magnesium, but Not Calcium Intake Is Significantly Association with Bone Mineral Status in 4 to 8 Year Old Children. Presentation at the Pediatric Academic Societies (PAS) annual meeting in Washington, D.C., May 2013.

Iodine supply in the womb may be linked to the child’s literacy

Mon, 20 May 2013 11:50:00 +0200

The longitudinal study examined standardized literacy test scores of 228 children at the age of nine who were born during a period of mild iodine deficiency in the population (1). The results showed that inadequate iodine exposure during pregnancy was associated with lasting effects: as nine-year-olds, the participants had lower scores on the test, particularly in spelling, compared to children with sufficient iodine supply. Inade-quate iodine exposure was not associated with lower scores on math tests.

The researchers commented that although the participants’ diet was fortified with iodine during childhood, later supplementation was not enough to reverse the impact of the deficiency during pregnancy. Iodine plays a key role in brain development and even mild deficiency during pregnancy can harm the baby’s neurological development. The scientists theorized that iodine deficiency may take more of a toll on the development of auditory pathways and, consequently, auditory working memory; thus there was more of an impact on stu-dents’ spelling ability than their mathematical reasoning ability.

The researchers emphasized that iodine deficiency during pregnancy is preventable: pregnant women should follow public health guidelines and take daily dietary supplements containing iodine. Public health supplemen-tation programs also can play a key role in monitoring how much iodine the population is receiving and acting to ensure at-risk groups receive enough iodine in their diet. In Australia, bread manufacturers began using iodized salt in October 2001 as part of a voluntary iodine fortification program.

1. Rebagliato M. et al. Iodine Supplementation During Pregnancy and Infant Neuropsychological Development: INMA Mother and Child @@Cohort Study. American Journal of Epidemiology. Published online April 2013.

Increased intakes of an omega-3 fatty acid may reduce aggressive behavior

Fri, 17 May 2013 15:00:00 +0200

This randomized controlled trial examined laboratory-based measures of aggression, impulsivity, and stress in 173 young adult men without a history of aggressive or impulsive behavior. They received either a supple-ment with vitamins (A, C, D, E, K and the B vitamins), minerals and trace elements, a supplement with doco-sahexaenoic acid (672 mg of DHA/day), a combination of both supplements, or a placebo for three months (1). The study results showed that participants who took DHA had a decrease in aggressive behavior and a decrease in impulsivity (the ability to inhibit already initiated behavior). The multivitamin, mineral and trace element supplement did decrease perceived stress but not the other parameters. No synergistic effects were observed in the group receiving vitamins/minerals plus DHA.

The researchers commented that previous studies may have shown positive findings with vitamin/minerals supplementation because they used participants who were deficient in micronutrients at the beginning of the study. Clearly, future studies would benefit from measuring the participants’ micronutrient status.

A series of @@randomized, placebo-controlled double-blind studies have reported that supplementation with vitamins/minerals, omega-3 @@fatty acids or both reduce the incidence of aggressive behavior in participants with a history of antisocial behavior. One study found that the disciplinary record of young male offenders improved by 26% following 13 vitamins plus 12 minerals and omega-3 @@fatty acid supplementation (80 mg/ day of eicosapentaenoic acid (EPA) and 44 mg/day of DHA) (2). A replication of this study used higher doses of @@fatty acids (400 mg of DHA and 400 mg of EPA per day), and found that aggression and rulebreaking decreased by 34% (3).

1. Long S.-J. and Benton D. A double-blind trial of the effect of docosahexaenoic acid and vitamin and mineral supplementation on aggression, impulsivity, and stress. Hum. Psychopharmacol Clin Exp. Published online May 2013.

2. Gesch C. B. et al. Influence of supplementary vitamins, minerals and essential @@fatty acids on the antisocial behaviour of young adult prisoners. @@Randomised, placebo- @@controlled trial. Br J Psychiatry. 2002; 181:22–28.

3. Zaalberg A. et al. Effects of nutritional supplements on aggression, rule-breaking, and psychopathology among young adult prisoners. Aggress Behav. 2010; 36:117–126.

High intakes of vitamin A and/or beta-carotene seem to not increase fracture risk

Wed, 15 May 2013 14:04:00 +0200

This intervention trial documented cases of fractures among 2,322 adults who had been previously exposed to asbestos (1). Initially, they received either 25,000 IU of vitamin A (retinyl palmitate) per day (7.5 mg retinol equivalents, RE), 30 mg beta-carotene per day, or 0.75 mg beta-carotene per day for six years; after that, all participants received 25,000 IU of vitamin A per day for 10 years. The study results showed that participants who took high doses of vitamin A for up to 16 years had no increased risk of fractures or any osteoporotic fracture risk. However, a decreased risk of fracture was associated with a greater duration of beta-carotene supplementation in men.

The researchers commented that, although both vitamin A and beta-carotene (a precursor of vitamin A) contribute to vitamin A intake, not all beta-carotene is converted to retinol, and so beta-carotene and vitamin A do not necessarily have the same effect on bone. Two observational studies have suggested that there is a protective relationship between beta-carotene and fracture risk, possibly through beta-carotene’s antioxidant capability (2, 3).

@@Observational studies examining vitamin A supplement use in relation to fracture risk have been mixed so far. A slightly increased risk for self-reported hip fracture, but not all fractures, was suggested among vitamin A supplement users in the Iowa Women’s Health Study, which followed over 34,000 post-menopausal women for an average of 9.5 years (4). However, no dose-response relationship was demonstrated, and hip fracture was not associated with dietary or total retinol intake. On the other hand, the Women’s Health Initiative @@Observational Study, which included over 75,000 post-menopausal women, the total retinol intake (from food and supplements) for an average of 6.6 years was not associated with risk for any fracture or hip fracture (5). To date, all of the @@observational studies in this field have included women only, with the majority focusing on post-menopausal women, while the present study included both men and women of a wide range of ages.

1. Ambrosini G. L. et al. No dose-dependent increase in fracture risk after long-term exposure to high doses of retinol or beta-carotene. Osteoporos Int. 2013; 24:1285–1293.

2. Sahni S. et al. Protective effect of total carotenoid and lycopene intake on the risk of hip fracture: a 17-year follow-up from the Framingham @@Osteoporosis Study. J Bone Min Res. 2009; 24:1086–1094.

3. Zhang J. et al. @@Antioxidant intake and risk of @@osteoporotic hip fracture in Utah: an effect modified by smoking status. Am J Epidemiol. 2006; 163:9–17.

4. Lim L. S. et al. Vitamin A intake and the risk of hip fracture in postmenopausal women: the Iowa Women’s Health Study. Osteopor Int. 2004; 15:552–559.

5. Caire-Juvera G. et al. Vitamin A and retinol intakes and the risk of fractures among participants of the Women’s Health Initiative @@Observational Study. Am J Clin Nutr. 2009; 89:323–330.

Treatment with omega-3 fatty acids may be not effective for cardiovascular patients

Tue, 14 May 2013 15:01:00 +0200

In the randomized controlled trial, 12,513 patients with multiple cardiovascular risk factors or atherosclerotic vascular disease (but not myocardial infarction) received daily omega-3 @@fatty acids (1 g fish oil including eicosapentaenoic acid and docosahexaenoic acid) or placebo for an average of 5 years (1). The study results showed neither greater @@reduction of mortality risk due to @@cardiovascular events nor a @@reduction in the risk of developing further @@cardiovascular complications among the omega-3 group compared with the placebo group.

The researchers conceded that all participants received pharmaceutical treatment (e.g., with ACE inhibitors, angiotensin-receptor blockers, diuretic agents, calcium-channel blockers, beta-blockers, oral hypoglycemic drugs, insulin, statins and antiplatelet agents), which makes the ability to measure (additional) benefits of omega-3 @@fatty acids less evident. Moreover, a number of participants had already reported fish in their diets (43% consumed fish once a week, 27% consumed fish twice a week). Omega-3 @@fatty acid blood levels were not measured. Experts commented the publicly available scientific data taken altogether does demonstrate a @@cardiovascular benefit of eicosapentaenoic acid and docosahexaenoic acid in healthy populations, as well as in the majority of populations with pre-existing @@cardiovascular ailments; thus, the new results cannot be generalized.

1. The Risk and Prevention Study Collaborative Group. n–3 @@Fatty Acids in Patients with Multiple @@Cardiovascular Risk Factors. N Engl J Med. 2013; 368:1800-1808.

Vitamin D may support recovery from muscle injury

Mon, 13 May 2013 08:19:00 +0200

In the study, 14 active adults were measured for muscular strength in the legs and blood vitamin D concen-trations before and after intense exercise (1). One of the participant’s legs was used for the muscle perfor-mance experiment, while the other acted as a control. The study results showed that muscle weakness was observed in the exercise leg compared with the control leg after physical activity. Low serum levels of vitamin D before, immediately after and 2 to 3 days after exercise were linked to increased immediate and persistent muscular weakness.

The researchers commented that future research should investigate the influence of diverse vitamin D interventions that maintain adequate blood levels on the alleviation of muscle weakness after muscle strain. Research has shown that proximal muscle weakness and diffuse muscle pain are prominent features of the clinical syndrome of vitamin D deficiency (2). The vitamin D receptor (VDR) is expressed in human muscle tissue and VDR activation may promote de novo protein synthesis in muscle. Several observational studies have suggested an association between increasing blood 25 hydroxyvitamin D concentrations and improved muscle strength or lower extremity function in the elderly. In addition, vitamin D supplementation has been shown to increase muscle strength and balance, and to reduce the risk of falling in community-dwelling individuals.

1. Barker T. et al. Higher @@serum 25-hydroxyvitamin D concentrations associate with a faster recovery of skeletal muscle strength after muscular injury. Nutrients. 2013; 5(4):1253-1275.

2. Bischoff-Ferrari H. A. Relevance of vitamin D in muscle health. Reviews in Endocrine and @@Metabolic Disorders. 2012; 13(1):71-77.

Many pregnant women do not meet iodine intake requirements

Fri, 10 May 2013 16:17:00 +0200

The analysis of data from a representative US population-based survey examined the iodine intake (based on urinary iodine concentrations) of 1,250 pregnant women and 5,154 women of reproductive age (between 15 and 39 years of age), and estimated their iodine intake from dietary supplements (1). The results showed that the median urinary iodine concentration (UIC) in the pregnant participants was 148 mcg/L, which has been defined as insufficient by the WHO (below 150 mcg/L). Although 77.5% of pregnant women reported taking one or more dietary supplements in the past 30 days, only 22.3% consumed an iodine-containing supplement. They had an estimated mean daily iodine intake of 122 mg from supplements (median value 144 mg/day). Among non-pregnant women who reported using supplements with iodine, the estimated mean daily iodine intake from supplements was 107 mg and the median UIC was 133 mcg/L, with 100 to 199 mcg/L defined as adequate.

The researchers commented that, because iodine is available in very few foods, dietary supplements may play a key role in ensuring that the population – particularly pregnant and non-pregnant women of child-bearing age and other subgroups at risk in the population – receives enough iodine for optimal health and optimal fetal development. Iodine is essential for adequate fetal and postnatal central nervous system growth and development. It is important to determine the iodine intake and status of both pregnant and non-pregnant women of reproductive age because the critical period of organogenesis comes before many women know that they are pregnant. The iodine requirement increases by over 50% during pregnancy. Iodine deficiency is the most frequent cause of preventable mental retar-dation globally. Although the burden of iodine deficiency in the US is lower than that in the developing world, it is still an important public health issue because some subgroups of pregnant and reproductive-aged women are still at risk for mild deficiency (2). The WHO defines iodine sufficiency in pregnancy as a median UIC of 150 to 249 mcg/L (3).

1. Gahche J. J. et al. The Prevalence of Using Iodine-Containing Supplements Is Low among Reproductive-Age Women, National Health and Nutrition Examination Survey 1999–2006. The Journal of Nutrition. Published online April 2013.

2. Perrine C. G. et al. Some subgroups of reproductive age women in the United States may be at risk for iodine deficiency. J Nutr. 2010; 140:1489–1494.

3. WHO. United Nations Children’s Fund and International Council for the Control of Iodine Deficiency Disorders. Assessment of iodine deficiency disorders and monitoring their elimination, a guide for programme managers. 3rd ed.; 2007.

Vitamin E may support cardiovascular health in former smokers

Wed, 08 May 2013 15:50:00 +0200

In the study, 30 smokers in their twenties who had smoked at least a pack of cigarettes a day for a year and had quit for one week received either 500 mg of vitamin E a day or a placebo for one week (1). At the start and at the end of the study, the participants’ blood was analyzed for markers of inflammation and vascular function (the blood vessels’ ability to dilate) was measured by taking ultrasound images of an upper arm artery before and after circulation was temporarily stopped. The study results showed that all of the participants had a 2.8% increase in vascular function owing to the fact that they had quit smoking, but those who also took a vitamin E supplement enjoyed an additional 1.5% of improved vascular function. Participants who took the vitamin E supplement also had lower levels of proteins closely linked to the body’s inflammatory system that can contribute to heart disease.

The researchers commented that although the study was small and the smokers only quit for a brief period of time, the results are meaningful given that prior work showed that every 1% increase in vascular function translated into a 13% drop in the risk of developing heart disease. Studies showed that it can take a decade or more after smokers stop smoking for their hearts to resemble those of non-smokers. It takes that long for some of the damage due to inflammation to subside and for the blood vessels to return back to their elastic, flexible selves so they are no longer contributing to an increased risk of heart problems (2). For smokers, quitting smoking should be the number one item on the health agenda, the scientists noted, but if one could enhance the effectiveness of smoking cessation and lower the risk of future heart disease by increased intakes of vitamin E, this would also have a significant impact from a public health perspective.

In the study, gamma-tocopherol, the most abundant vitamin E form in the American diet, was used. Usually, vita-
min E studies use alpha-tocopherol, the best investigated vitamin E form. Vitamin E is regarded as a very effective antioxidant that protects against damage to lipids and prevents the oxidation of lipoproteins and polyunsaturated fatty acids in the body, which is caused by free radicals. Smokers are well-known to have increased @@oxidation of those fats in the body and, based on prior studies, vitamin E has been touted as a nutrient that may help mitigate that damage.

1. Bruno R. et al. Water and Fat Soluble Vitamins and @@Chronic Disease. Symposium held in April 2013 at the Experimental Biology meeting in Boston, USA.

2. American Heart Association. Smoking & @@Cardiovascular Disease. Updated: Feb 2013. http://www.heart.org/HEARTORG/GettingHealthy/QuitSmoking/QuittingResources/Smoking-Cardiovascular-Disease_UCM_305187_Article.jsp

Lutein plus zeaxanthin supplementation may benefit AMD patients with insufficient dietary intakes

Tue, 07 May 2013 16:20:00 +0200

This randomized controlled trial included 4,203 participants, aged 50 to 85, who had age-related macular degeneration (AMD) and were at risk for progression to advanced @@AMD (1). In addition to the original AREDS formulation (2) – a high-dose daily intake of vitamin C (500 mg), vitamin E (400 IU), beta-carotene (15 mg), zinc (80 mg as zinc oxide), and copper (2 mg as cupric oxide) – participants were asked to take either lutein (10 mg) plus zeaxanthin (2 mg), docosahexaenoic acid (350 mg as DHA) plus eicosapentaenoic acid (650 mg as EPA), both of them, or placebo daily for an average of five years. The study results showed that the AREDS2 formulation did not show an additional @@reduction of the participants’ risk in progressing to advanced AMD (compared with the effect of disease risk @@reduction measured for the AREDS formulation before). However, a 26% lower risk of progression to advanced @@AMD (1) and a 32% lower risk of cataract surgery (3) were shown in participants with the lowest dietary intake of lutein plus zeaxanthin. Also, an elevated risk of lung cancer in the group of former smokers who received a high dose of beta-carotene was observed compared to the group of people who received multivitamins without beta-carotene (a 2% and 1% higher risk, respectively).

The researchers commented that the study enrolled a population of well-nourished people and that there might be benefits of additional supplemented micronutrients for @@AMD patients who are less well-nourished. For example, in the US, dietary intake of lutein and zeaxanthin is typically less than 1 mg per day. As the number of cases of lung cancer was small and the analyses of mortality risk in the beta-carotene group of former smokers and all other groups showed essentially no change in rates, the results may not be generali-zable, the scientists noted. In 2012, the European Food Safety Authority (EFSA) concluded that exposure to beta-carotene from its use as a food additive and as a food supplement at levels below 15 mg/day should not give rise to concern about adverse health effects in the general population, including heavy smokers (4).

The Age-Related Eye Disease Study (AREDS) demonstrated that daily oral supplementation with antioxidant vitamins and minerals @@reduced the risk of developing advanced @@AMD as secondary prevention by 25% five years later (2) and 34% 10 years later (5). In addition, observational studies suggested that higher dietary intake of lutein plus zeaxanthin, omega-3 long-chain @@polyunsaturated @@fatty acids (DHA and EPA), or both are associated with a decreased risk of developing advanced @@AMD (6, 7). Lutein and zeaxanthin are the main components of the macular pigment. DHA is a major structural component of the retina, and EPA may play a role as a precursor to signaling molecules with potential to influence retinal function.

1. The AREDS2 Research Group. Lutein + Zeaxanthin and Omega-3 @@Fatty Acids for Age-Related @@Macular Degeneration: The Age-Related Eye Disease Study 2 (AREDS2) @@Randomized @@Clinical Trial. JAMA. Published online May 2013.

2. Age-Related Eye Disease Study Research Group. A @@randomized, placebo-controlled, @@clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related @@macular degeneration and vision loss: AREDS report no. 8. Arch Ophthalmol. 2001; 119(10):1417-1436.

3. The AREDS2 Research Group. Lutein/Zeaxanthin for the treatment of age-related @@cataract. JAMA Ophthalmol. Published online May 2013.

4. EFSA Panel on Food Additives and Nutrient Sources added to Food. Statement on the safety of beta-carotene use in heavy smokers. EFSA Journal 2012; 10(12):2953.

5. Chew E. Y. et al. Long-Term Effects of Vitamins C and E, β-Carotene, and Zinc on Age-Related @@Macular Degeneration: AREDS Report No. 35. Ophthalmology. Published online April 2013.

6. SanGiovanni J. P. et al; Age-Related Eye Disease Study Research Group. Omega-3 Long-chain @@polyunsaturated @@fatty acid intake and 12-y incidence of neovascular age-related @@macular degeneration and central geographic atrophy: AREDS report 30, a @@prospective @@cohort study from the Age-Related Eye Disease Study. Am J Clin Nutr. 2009; 90:1601-1607.

7. Augood C. et al. Oily fish consumption, dietary docosahexaenoic acid and eicosapentaenoic acid intakes, and associations with neovascular @@age-related @@macular degeneration. Am J Clin Nutr. 2008; 88(2):398-406.