Search

Background: In 2016, the Norwegian National Nutrition Council concluded that inadequate iodine intake is widespread in sections of the Norwegian population, and that effective measures should be undertaken immediately. This literature review aims to summarise articles published since January 2016 that describe the iodine intake in Norway., Material and Method: Literature searches were conducted in PubMed and Embase. Altogether thirteen articles that reported intake of iodine from the diet or urinary iodine concentration were included., Results: The recent studies confirm that inadequate iodine intake is widespread among women of fertile age, pregnant and breastfeeding women, infants who are exclusively breastfed, elderly persons, vegans and immigrants. There are few sources of iodine in the diet, and persons who avoid or have a low intake of milk and white fish are particularly vulnerable., Interpretation: Inadequate iodine intake is a matter of particular concern in women of fertile age. Healthcare personnel should be aware of this and in certain cases recommend iodine-rich foods or iodine supplements to these and other vulnerable groups.

Background: CLA (conjugated linoleic acid) supplements are advertised as a way to reduce weight and to obtain a "better balance between fat and muscle". What evidence is there for these health claims, and is CLA supplementation safe and without adverse effects?, Material and Methods: This review is based on peer-reviewed scientific publications., Results: Large doses of CLA supplements in rodents reduce fat mass and increases muscle mass, but the results from 13 randomised, placebo-controlled clinical studies do not support these findings with regard to humans. However, results from both animal and human studies indicate that the CLA isomer 10-trans,12-cis may have a negative impact on carbohydrate and lipid metabolism by inducing insulin resistance and hyperlipidaemia. Studies of CLA supplementation to lactating women have revealed lower fat content in their milk. Furthermore, the cordial blood concentration of CLA in women has been shown to correlate negatively with both gestational length and birth weight., Conclusion: Even if reduced weight and fat mass has been observed in animal models following CLA supplementation, the basis is, at best, weak for such claims in humans. Provided that the fat mass reducing effect of CLA is mediated through PPARgamma, this may result in adverse metabolic effects.

Both laymen and the learned are discussing the need for vitamin and minerals supplements and their eventual preventive and therapeutic potential. Documentation is needed, but this word is most of the time used without clarifying the criteria it is based on. In this article we use vitamin E in order to illustrate that there is generally a long way to go from initial hypothesis to eventual practical advice and recommendations. Promising cell and animal studies combined with epidemiological observation studies are not sufficient as evidence; randomised intervention studies are required before conclusions can be drawn. Because high intakes of vitamins and minerals can have negative health effects, we also present the work carried out to decide upper safe intake levels in the Nordic countries, the EU and the USA. Women of fertile age should under certain circumstance take iron and folate supplements, and everyone in Scandinavia should take a supplement with vitamin D. It is sensible and harmless to take a multivitamin and mineral pill for people in risk groups, e.g. people eating very little or have an unbalanced diet (children, old people, patients). Except for these groups it is poorly documented that vitamins and minerals in large doses have a preventive or therapeutic potential. The largest health potential lies in a healthy diet.