Kiely M, Flynn A, Harrington KE, Robson PJ, O'Connor N, Hannon EM et al.. The efficacy and safety of nutritional supplement use in a representative sample of adults in the North/South Ireland Food Consumption Survey. Public Health Nutr 4, 1089-1097

Department of Food Science, Food Technology and Nutrition, University College, Cork, Republic of Ireland.
Public Health Nutrition (Impact Factor: 2.68). 10/2001; 4(5A):1089-97. DOI: 10.1079/PHN2001190
Source: PubMed


To describe the current use of nutritional supplements and their contribution to micronutrient intakes in a representative sample of Irish adults, to evaluate the impact of supplement use on the adequacy of micronutrient intakes and to assess the risk to supplement users of exceeding tolerable upper intake levels (UL).
Food intake data were collected in 1379 (662 male and 717 female) randomly selected Irish adults aged 18 to 64 years using a 7-day food diary. The current use of nutritional supplements was assessed using a self-administered questionnaire and respondents entered each supplement as it was consumed into the food diary.
Twenty-three per cent of respondents regularly used nutritional supplements. Twice as many women used supplements as men. The intakes of micronutrients were significantly higher (P<0.001) in supplement users than in non-users. Micronutrient intakes from food sources were similar in male users and non-users of supplements, but were significantly higher (P<0.01) in female users, by 3 to 13%, for Fe, Mg, Mn, vitamins C and E and niacin than in non-users. The percentage of female users between 18 and 50 years who had mean Fe intakes below the average requirement (AR) (10 mg) decreased from 50 to 25 when the contribution from supplements was included. The use of supplements reduced the percentage of men who had mean intakes below the AR for Zn from 19 to 13, for riboflavin from 14 to 6 and for vitamin A from 20 to 5, and reduced the percentage of women with intakes below the AR for Ca from 23 to 16 and for riboflavin from 23 to 14. Twenty-one women out of 80 aged between 18 and 50 years, who consumed supplemental folate, achieved the intake of 600 microg recommended to prevent neural tube defects. Twenty-two per cent of the women who took iron and 15% of the women who took vitamin B6 in supplemental form had mean daily intakes that exceeded that UL for these nutrients. Supplement users did not exceed the UL for the other micronutrients.
Supplementation appears to be beneficial in promoting adequate intakes of some micronutrients, particularly Fe and folate in women aged 18-50 years and vitamin A in men. There appears to be little risk to supplement users of experiencing adverse side effects due to excessive intakes of micronutrients.

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    • "However, evidence seems to suggest that the population intake of vitamin D from supplements is quite low (19). For example, although supplements contribute ∼12 and 7% to vitamin D intakes in Irish women and men, respectively (33) and almost a quarter of vitamin D intakes in women and 12% in men in the UK (20), overall intakes are low so these contributions while proportionally high are quantitatively low. This is a function mainly of the relatively low vitamin D content of most supplements in some countries relative to requirement as discussed above. "
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    ABSTRACT: There is little doubt that vitamin D deficiency across all age groups in Europe is a problem. Low vitamin D status arises due to limited, if any, dermal synthesis during the winter months at latitudes above 40°N, putting increased importance on dietary supply of the vitamin. However, dietary intakes by most populations are low due to the limited supply of vitamin D-rich foods in the food chain. Thus strategies that effectively address this public health issue are urgently required. It has been emphasized and re-emphasized that there are only a limited number of public health strategies available to correct low dietary vitamin D intake: (1) improving intake of naturally occurring vitamin D-rich foods, (2) vitamin D fortification (mandatory or voluntarily) of food, and (3) vitamin D supplementation. Recent evidence suggests that the levels of vitamin D added to food would need to be high so as to ensure dietary requirements are met and health outcomes optimized. In addition, knowledge of the most effective forms of vitamin D to use in some of these preventative approaches is important. There is still uncertainty in relation to the relative efficacy of vitamin D(2) versus D(3), the two main food derived forms and those used in vitamin D supplements. The major metabolite of vitamin D with biological activity is 1,25(OH)(2)D; however, this is usually used for pharmacological purposes and is not typically used in normal, healthy people. The other major metabolite, 25(OH)D, which has also been used for pharmacological purposes is present in certain foods such as meat and meat products (particularly offal) as well as eggs. This metabolite may have the potential to boost vitamin D status up to five times more effectively that native vitamin D(3) in foods. However, the exact bioactivity of this compound needs to be established.
    Food & Nutrition Research 04/2012; 56. DOI:10.3402/fnr.v56i0.5383 · 1.79 Impact Factor
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    • "This indicates a very low risk of adverse effects from excessive intakes of micronutrients in the population. A small proportion (0·1 –2·2 %) of FF consumers had MDI of folic acid, vitamin B 6 , retinol, Ca, Zn, and vitamin E that exceeded the UL but this was mainly associated with the use of nutritional supplements (Kiely et al. 2001) or, in the case of retinol, of high liver consumption and was not affected by fortification, which contributed only small amounts to the intakes of these micronutrients relative to their UL. For example, 1·2 % of FF consumers (mainly women) exceeded the UL for vitamin B 6 (25 mg) with average daily intakes ranging from 30 –62 mg, mainly from supplements , while one FF consumer (male) exceeded the UL for Ca (2500 mg "
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    ABSTRACT: The objective of this work was to quantify the impact of the voluntary fortification of foods on dietary intakes of vitamins and minerals of Irish adults. Foods that were voluntarily fortified were identified and pre- and post-fortification levels of micronutrients were determined from data supplied by manufacturers and food composition tables. Using food consumption data in 1379 adults aged 18-64 years, estimated using a 7-d food diary during the North/South Ireland Food Consumption Survey, intakes of micronutrients were determined, both including and excluding the fortification component in foods. Of approximately 3000 foods recorded as consumed, 1.9 % were fortified, mainly breakfast cereals and beverages. Median micronutrient content of fortified foods (FF) ranged from 18-33 % EC RDA per typical serving. Among consumers (65 % of men, 68 % of women), FF contributed, on average, 3.9 % (men) and 5.0 % (women) to mean daily intake (MDI) of energy. Relative to their contribution to MDI of energy, FF contribute a greater % MDI for Fe (men 16, women 19), folate (men 18, women 21), vitamins B1 (men 14, women 16), B2 (men 16, women 18), B6 (men 12, women 15), D (men 5, women 11), B12 (men 5, women 7) and niacin (men 10, women 12). Fortification significantly improved the adequacy of intake of some micronutrients, particularly of riboflavin, folate, vitamin D and Fe in women and did not contribute to an increased risk of adverse effects from excessive intake of any micronutrient.
    British Journal Of Nutrition 07/2007; 97(6):1177-86. DOI:10.1017/S0007114507669207 · 3.45 Impact Factor
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    • "The present study aimed to assess the Zn status of healthy late middle-aged and older Europeans and to investigate the effects of Zn supplementation on their cognitive functioning. Note that even if the sample were not Zn deficient, there may be advantages in consuming some nutrients at levels beyond average requirements (Kiely et al. 2001). Moreover, we need to establish that supra-nutritional doses of Zn have no adverse effects. "
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    ABSTRACT: A randomised double-blind placebo-controlled design was employed to investigate the effects of Zn supplementation on cognitive function in 387 healthy adults aged 55-87 years. Several measures of visual memory, working memory, attention and reaction time were obtained using the Cambridge Automated Neuropsychological Test Battery at baseline and then after 3 and 6 months of 0 (placebo), 15 or 30 mg Zn/d. Younger adults (< 70 years) performed significantly better on all tests than older adults (> 70 years), and performance improved with practice on some measures. For two out of eight dependent variables, there were significant interactions indicating a beneficial effect (at 3 months only) of both 15 and 30 mg/d on one measure of spatial working memory and a detrimental effect of 15 mg/d on one measure of attention. Further work is required to establish whether these findings generalise to older adults in poorer mental and physical health and with less adequate Zn intake and status than the present sample.
    British Journal Of Nutrition 10/2006; 96(4):752-60. · 3.45 Impact Factor
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