Risk Assessment of "Other Substances" – L-aspartic Acid

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk of "other substances" in food supplements and energy drinks sold in Norway. VKM has assessed the risk of doses in food supplements and concentrations in energy drinks given by NFSA. These risk assessments will provide NFSA with the scientific basis while regulating the addition of "other substances" to food supplements and other foods. "Other substances" are described in the food supplement directive 2002/46/EC as substances other than vitamins or minerals that have a nutritional and/or physiological effect. It is added mainly to food supplements, but also to energy drinks and other foods. VKM has not in this series of risk assessments of "other substances" evaluated any claimed beneficial effects from these substances, only possible adverse effects. The present report is a risk assessment of specified doses of L-aspartic acid in food supplements, and it is based on previous risk assessments and articles retrieved from literature searches. According to information from NFSA, L-aspartic acid is an ingredient in food supplements sold in Norway. NFSA has requested a risk assessment of 3000, 3500, 4000, 4500, 5000 and 5700 mg/day of L-aspartic acid in food supplements. L-aspartic acid is a dispensable dicarboxylic amino acid that can be produced by the transamination of oxaloacetic acid, an intermediate in the metabolism of e.g. glucose and some amino acids. L-aspartic acid is present in frequently consumed foods of animal and plant origin and is also a component of the sweetener aspartame. Dietary intake of aspartic acid in Norway is not known, but data from NHANES III (USA) suggest a mean dietary intake of about 6.5 g/day in adults. The highest intake was seen in men 31 through 50 years of age at the 99th percentile of 15.4 g/day. In the literature review we did not identify any long-term studies in human individuals that could be used for risk assessment. Short-term human studies found no adverse health effect when L-aspartic acid was given in acute doses ranging from 1 to 10 g/day, for time periods between one single dose and four weeks. None of these studies were undertaken to assess the toxicity of L-aspartic acid. In the literature search, two animal studies were identified of which one was a 90-day subchronic toxicity study. In that study, a no observed adverse effect level (NOAEL) of 697 mg/kg bw per day in male rats and 715 mg/kg bw per day in female rats was established. No neurotoxicity was found, however a toxic effect on kidneys and possibly salivary glands was observed at 1400 mg/kg bw per day (lowest observed adverse effect level, LOAEL). For the risk characterisation, the NOAEL of 697 mg/kg bw per day derived from the abovementioned subchronic toxicity study in rats was used for comparison with the estimated exposures from food supplements. The calculated Margin of Exposure (MOE) values for this NOAEL ranged from 5 to 16 for a daily intake of 3000-5700 mg/day of Laspartic acid. These low MOE-values may not be regarded as acceptable since L-aspartic acid has caused toxic effects on the kidneys (regenerative renal tubules with tubular dilation) and acinar cell hypertrophy of salivary glands in rats. Further, direct information regarding potential adverse health effects in humans is not available due to absence of long-term studies. In adults (≥18 years), adolescents (14 to < 18 years) and children (10 to < 14 years), the specified doses 3000, 3500, 4000, 4500, 5000 and 5700 mg/day L-aspartic acid in food supplements may represent a risk of adverse health effects. Children younger than 10 years were not within the scope of the present risk assessment.

Risk Assessment of "Other Substances" – Glycine

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk of "other substances" in food supplements and energy drinks sold in Norway. VKM has assessed the risk of doses given by NFSA. These risk assessments will provide NFSA with the scientific basis while regulating "other substances" in food supplements. "Other substances" are described in the food supplement directive 2002/46/EC as substances other than vitamins or minerals that have a nutritional and/ or physiological effect. It is added mainly to food supplements, but also to energy drinks and other foods. In this series of risk assessments of "other substances" VKM has not evaluated any claimed beneficial effects from these substances, only possible adverse effects. The present report is a risk assessment of specified doses of glycine in food supplements, and it is based on previous risk assessments and articles retrieved from two literature searches. Glycine is a non-essential amino acid which is synthesised from 3-phosphoglycerate via serine, or derived from threonine, choline and hydroxyproline via inter-organ metabolism involving primarily the liver and kidneys. Endogeneous synthesis is estimated to be in the magnitude of 8 g per day in adults. Glycine is a constituent of all proteins in the human body. It also functions as a neurotransmitter, and can play both stimulatory and depressant roles in the brain. Data on dietary intake of glycine in Norway are not available. Based on NHANES III (1988-1994), the overall mean intake of glycine from food and food supplements in the United States was 3.2 g per day. Thus, the combined dietary intake and endogenous synthesis is more than 11 g per day. Because glycine is not considered an essential amino acid, a dietary requirement in healthy humans has not been established. Foods rich in glycine are generally protein rich foods such as meat, fish, dairy products and legumes. According to information from NFSA, glycine is an ingredient in food supplements sold in Norway. NSFA has requested a risk assessment of 20, 50, 100, 300, 500 and 650 mg/day of glycine from food supplements. There is a lack of relevant supplementation studies with glycine in humans designed to address adverse effects and/or dose-response relationship, and none of the previous reports reviewed concluded with a no observed adverse effect level (NOAEL). For the current risk assessment, two literature searches were conducted, one for human studies and one for animal studies. No human studies were found that can be used for suggesting a "value for comparison", and there are no scientific data in the published literature suitable for assessing the specific doses in the terms of reference. The value for comparison used in this risk characterisation is 20 mg/kg per day. This value is derived from a study in rats in which the NOAEL was estimated at 2000 mg/kg per day. Using an uncertainty factor of 100, this corresponds to 20 mg/kg per day or 1.4 g per day for a person weighing 70 kg. This is more than twice as high as the highest dose for consideration in the present risk assessment, and it is far below the combined dietary intake and endogenous synthesis estimated at more than 11 g per day. No particular vulnerable groups for glycine supplements have been identified. VKM concludes that: In adults (≥18 years), the specified doses 20, 50, 100, 300, 500 and 650 mg/day of glycine from food supplements are unlikely to cause adverse health effects. In adolescents (14 to <18 years), the specified doses 20, 50, 100, 300, 500 and 650 mg/day of glycine from food supplements are unlikely to cause adverse health effects. In children (10 to <14 years), the specified doses 20, 50, 100, 300, 500 and 650 mg/day of glycine from food supplements are unlikely to cause adverse health effects. Children younger than 10 years were not within the scope of the present risk assessment.

Risk Assessment of "Other Substances" – L-proline

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk of "other substances" in food supplements and energy drinks sold in Norway. VKM has assessed the risk of doses given by NFSA. These risk assessments will provide NFSA with the scientific basis while regulating "other substances" in food supplements. "Other substances" are described in the food supplement directive 2002/46/EC as substances other than vitamins or minerals that have a nutritional and/ or physiological effect. It is added mainly to food supplements, but also to energy drinks and other foods. In this series of risk assessments of "other substances" VKM has not evaluated any claimed beneficial effects from these substances, only possible adverse effects. The present report is a risk assessment of specified doses of L-proline in food supplements, and it is based on previous risk assessments and articles retrieved from literature searches. According to information from NFSA, L-proline is an ingredient in food supplements sold in Norway. NSFA has requested a risk assessment of 50, 500, 1000, 1500 and 1800 mg/day of L-proline from food supplements. L-proline is considered a non-essential amino acid as it can be synthesised from arginine via the urea cycle in liver, and from glutamine/glutamic acid in the intestinal epithelium. In addition, L-proline is ingested through the diet. All protein rich foods provide L-proline, and animal proteins from milk and meat are particularly abundant sources. A dietary requirement for proline in healthy humans has not been estimated since proline is not considered an essential amino acid. Data on dietary intake of L-proline in Norway are not available. In the third US National Health and Nutrition Examination Survey (NHANES III; 1988-1994), overall mean intake of L-proline from food and supplements was 5.2 g/day. A previous report from the Institute of Medicine (2005) cited one small uncontrolled patient study (n=4) and two animal studies, none of which assessed the toxicity of L-proline in a dose-response manner. The report concluded that a tolerable upper intake level for L-proline could not be determined. In a risk grouping of amino acids from VKM (2011), proline was categorised as having potentially moderate risk, based on the scarce literature and the notion that amino acids are generally bioactive compounds. It was stated that "no conclusion can be drawn on a scientific basis due to lack of adequate scientific literature. Nor will it be possible to conduct a risk assessment until further studies are available". Three systematic literature searches without restriction on publication year were performed for the current risk assessment, aimed at identifying adverse effects of L-proline supplementation in human and animal studies. In humans, one uncontrolled experimental study was identified where a single oral dose of 500 mg/kg bw L-proline was administered as a growth hormone stimulatory agent to 20 children with hyposomatotropic dwarfism and 20 healthy children. No adverse effects were observed. In animals, one relevant subchronic (90 days) toxicological dose-response study in rats was included and forms the basis for the current risk assessment. In that study, performed in accordance with official guidelines from the Japanese Ministry of Health, Labour and Welfare, there were no indications of toxicity at the highest dose given through a powder diet (5.0% L-proline). This dose corresponded to 2773 mg L-proline/kg bw per day and was used as a no-observed-adverse-effect-level (NOAEL). Studies to set a tolerance level for L-proline for children or adolescents have not been found. Therefore, an assumption is made that these age groups have similar tolerance as adults relative to their body weight. To evaluate the safety of the specific doses given by NFSA, margin of exposure (MOE) was calculated with use of 2773 mg L-proline/kg bw per day as NOAEL. For the highest dose (1800 mg/day) MOE is 67 (= 2773* 43.3/1800) in children 10 to <14 years (default body weight 43.3 kg), and 94 (= 2773* 61.3/1800) in adolescents 14 to <18 years (default body weight 61.3 kg). For the dose of 1500 mg/day, the MOE in children is 80. MOE for all the other doses and age categories are above 100. Based on the magnitude of MOE, the lack of adverse effects at the highest dose tested (current NOAEL) and the notion that L-proline is a nutrient that is synthesised endogenously from other amino acids in addition to a dietary intake in the magnitude of 5 grams per day, VKM concludes that: In adults (≥18 years), the specified doses 50, 500, 1000, 1500 and 1800 mg/day Lproline in food supplements are unlikely to cause adverse health effects. In adolescents (14 to <18 years), the specified doses 50, 500, 1000, 1500 and 1800 mg/day L-proline in food supplements are unlikely to cause adverse health effects. In children (10 to <14 years), the specified doses 50, 500, 1000, 1500 and 1800 mg/day L-proline in food supplements are unlikely to cause adverse health effects. Children younger than 10 years were not within the scope of the present risk assessment.

Risk Assessment of "Other Substances" – Creatine

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk of "other substances" in food supplements sold in Norway. VKM has assessed the risk of doses given by NFSA. These risk assessments will provide NFSA with the scientific basis for regulating the addition of "other substances" to food supplements and other foods. "Other substances" are described in the food supplement directive 2002/46/EC as substances other than vitamins or minerals that have a nutritional and/ or physiological effect. It is added mainly to food supplements, but also to energy drinks and other foods. VKM has not in this series of risk assessments of "other substances" evaluated any potential beneficial effects from these substances, only possible adverse effects. The present report is a risk assessment of creatine as food supplement, and is based on previous risk assessments and articles retrieved in literature searches. According to information from the Norwegian Food Safety Authority (NFSA), creatine is an ingredient in food supplements sold in Norway, and NFSA has requested a risk assessment of the following doses of creatine in food supplements: 3.0, 5.0, 10.0 and 24.0 g/day. The average daily intake from the diet is about 1 g creatine, and the endogenous production also amounts to about 1 g/day. Most of the creatine supplements are in the form of creatine monohydrate. Creatine is an organic acid occurring in the body as either phosphocreatine (2/3) or as free creatine (1/3). Phosphocreatine provides phosphate groups for synthesis of adenosine triphosphate, the major energy-providing compound in the body. Previous risk assessments (AESAN, 2012; EFSA, 2004; SCF, 2000; VKM, 2010) all concluded that creatine supplementation with 3.0 g/day is unlikely to cause adverse health effects in adults. This is supported by human and animal data obtained in a literature search and assessed in the present report. Most of the studies with daily creatine intake above 3 g often (i) involved few and highly trained individuals of whom some took high daily loading doses of creatine for a short period, and (ii) were designed to test clinical benefit without emphasis on possible adverse effects. VKM therefore considers that there is insufficient evidence to conclude regarding possible adverse effects at doses of creatine above 3 g/day for the general population. VKM concludes that: In adults (≥ 18 years) the specified dose of 3.0 g/day creatine in food supplements is considered unlikely to cause adverse health effects. The documentation for absence of adverse health effects of doses 5.0, 10.0 and 24.0 g/day creatine in food supplements in the general population is limited. Hence, these doses may represent risk of adverse health effects in adults. In children (10-14 years) and adolescents (14-17 years), the specified doses of 3.0, 5.0, 10.0 and 24.0 g/day creatine in food supplements may represent a risk of adverse health effects. Children below 10 years were not included in the terms of reference.

Risk Assessment of "Other Substances" – L-leucine, L-isoleucine and L-valine, the Branched Chain Amino Acids (BCAA)

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk of "other substances" in food supplements and energy drinks sold in Norway. VKM has assessed the risk of doses given by NFSA. The risk assessments are the scientific basis for NFSA in its efforts to regulate the use of "other substances" to food supplements. "Other substances" are described in the food supplement directive 2002/46/EC as substances other than vitamins or minerals that have a nutritional and/or physiological effect. It is added mainly to food supplements, but also to energy drinks and other foods. VKM has not in this series of risk assessments of "other substances" evaluated any claimed beneficial effects from these substances, only possible adverse effects. The present report is a risk assessment of L-leucine, L-isoleucine and L-valine and it is based on previous risk assessments and articles retrieved from a literature search. In this report Lleucine, L-isoleucine and L-valine may occasionally be termed merely leucine, isoleucine or valine. L-leucine, L-isoleucine and L-valine are essential amino acids. L-leucine, L-isoleucine and Lvaline are commonly known as Branched Chain Amino Acids (BCAAs), and are found in food items containing proteins and in particular, in protein-rich foods such as dairy products, meats, eggs, nuts, whole grains, seeds, avocadoes and edible seaweed. According to information from NFSA, L-leucine, L-isoleucine and L-valine are ingredients in food supplements sold in Norway. NFSA has requested a risk assessment of the following doses of L-leucine, L-isoleucine and L-valine in food supplements for adults, adolescents and children 10 years and above: L-leucine: 2500, 3000, 4000, 5000 and 5250 mg/day, Lisoleucine: 1500, 1750, 2000 and 2500 mg/day and L-valine: 1500, 1750, 2000, 2250 and 2500 mg/day. Usual dietary intakes of these amino acids in Norway are not known. Based on data from the 1988–1994 NHANES III, mean daily intakes in adults of leucine, isoleucine and valine from food and supplements are 6.1, 3.6 and 4.0 g/day, respectively (IOM, 2005). Most studies on BCAAs have focused on the three amino acids taken as single amino acids or together combined in food supplements. It has been shown that BCAAs are not metabolized in the liver as is common for most other amino acids but taken up by most peripheral tissues (in particular muscle) where they are either used in protein synthesis or as precursors for nitrogen and/or a number of carbon containing molecules. There is a lack of relevant well-designed supplementation studies with L-leucine, L-isoleucine and L-valine in humans designed to address adverse effects and dose-response relationships as primary outcome. However, daily doses of as much as 30 g BCAA per day given to athletes have been investigated and reported to improve performance. In these reports adverse effects were not addressed and not reported. L-leucine has been administered orally in single doses for one day of up to 50 g without showing any adverse effects. There are no published studies on the effects of longitudinal supplementation with either L-isoleucine or L-valine. Thus, there are no published studies that can be used for suggesting a "value for comparison", and there is no scientific data in the literature suitable for assessing the specific doses in the terms of reference. WHO (2007) recommendations for BCAAs are: Leucine 2730 mg/day, isoleucine 1400 mg/day and valine 1820 mg/day. For a 70 kg person, this corresponds to 39 mg leucine/kg body weight (bw) per day, 20 mg isoleucine/kg bw per day and 26 mg valine/kg bw per day. The acute upper tolerable metabolic limit of L-leucine for men between 20 and 35 years was determined by administration of single doses of 550-700 mg/kg bw over one day. This corresponded to 39 to 50 g/day for a person of 70 kg. Furthermore, based on several studies investigating L-leucine, L-isoleucine and L-valine supplemented as single doses ranging from 10 to 30 g/day without any reported adverse effects. The uncertainties for this consideration are described in chapter 5. VKM concludes that: Due to lack of studies addressing adverse effects for the specified doses 2500, 3000, 4000, 5000 and 5250 mg/day L-leucine, 1500, 1750, 2000 and 2500 mg/day L-isoleucine and 1500, 1750, 2000, 2250 and 2500 mg/day L-valine in food supplements, no conclusions can be made for adults (≥ 18 years), adolescents (≥ 10 and < 18 years) or children (< 10 years).

Assessment of Iron Intake in Relation to Tolerable Upper Intake Levels

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the intake of iron in the Norwegian population in relation to tolerable upper intake levels (ULs). The existing maximum limit for iron in food supplements is 27 mg/day. VKM has also conducted scenario calculations to illustrate the consequences of amending the maximum limit to 5, 10, 20, 30, 40 or 50 mg/day. Iron deficiency is one of the most common nutritional disorders in the world. Individuals with increased iron demand such as growing children and pregnant women, those who experience blood loss such as menstruating women are particularly at risk for the consequences or iron deficiency. Iron deficiency can lead to fatigue and anaemia. The most common adverse effects of iron supplementation are reversible gastrointestinal symptoms. Chronic iron excess can lead to iron overload which is associated with several irreversible severe health outcomes such as cancers and cardiovascular diseases. Up to 1% of the population have a genetic trait that leads to accumulation of iron and renders them more vulnerable to iron excess. An adult needs approximately 10 mg iron per day to overcome daily loss. The tolerable upper intake level (UL) for iron in adults range from 45 to 60 mg/day. However, all previous reports acknowledge the challenges in defining upper levels. The Expert Group on Vitamins and minerals (EVM), UK report provided a guidance level (GL) of 17 instead of a UL and the Nordic Nutrition Recommendations (NNR) (2012) suggested an UL of 60 mg/day, but did not suggest any clear upper levels for children. Institute of Medicine (IOM), US (2001) gives the most substantiated tolerable upper intake levels based on gastrointestinal effects, which is 40 mg/day for infants and children, regardless of age, and 45 mg/day for adolescents and adults. The Joint FAO/WHO Expert Committee on Food Additives 2003 (JECFA) also took the potential serious effects of iron overload into account and suggested a GL of 50 mg/day in adults or 0.8 mg/kg per day in children and adolescents. Because the risks and consequences from overload are significant and potentially serious, VKM suggests that the GL from JECFA (2003) is used. Using the GL from JECFA (2003), none of the suggested doses can be given to 2 or 4-yearold children, 9 year olds can add 5 mg iron from supplements, 13 year olds 20, and adults 30 mg without exceeding the guidance levels.

Assessment of Vitamin B6 Intake in Relation to Tolerable Upper Intake Levels

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the intake of vitamin B6 (pyridoxine) in the Norwegian population in relation to tolerable upper intake levels (ULs). The existing maximum limit for vitamin B6 in food supplements is 4.2 mg/day. VKM has also conducted scenario calculations to illustrate the consequences of amending the maximum limitto 2, 6, 8, 10, 20 or 25 mg/day. Vitamin B6 is water soluble and comprises six compounds with vitamin B6 activity; pyridoxine (PN, an alcohol), pyridoxal (PL, an aldehyde) and pyridoxamine (PM, the amine) and their corresponding phosphates; pyridoxine 5’-phosphate (PNP), pyridoxal 5’ -phosphate (PLP) and pyridoaxamin 5’ –phosphate (PMP). These six forms of vitamin B6 are all present in food in addition to the glycosylated form, pyridoxine-5’-β-δ-glucoside (PNG), in some plants. In food supplements the most common vitamin B6 form is pyridoxine hydrochloride. Eighty to ninety percent of vitamin B6 in the body is found in muscles and estimated body stores in adults amount to about 170 mg with a half-life of 25-33 days. Vitamin B6 deficiency is mostly seen in combination with deficiency of other B vitamins. Symptoms of vitamin B6 deficiency are anaemia and neurological abnormalities (EFSA, 2016). Intakes of vitamin B6 from the diet alone have not been reported to cause adverse effects. Sensory neuropathy has been reported to be the most sensitive adverse health effect of vitamin B6 supplementation. VKM proposes to adopt the tolerable upper intake level (UL) set by the Scientific Committee for Food (SCF) in 2000 at 25 mg/day for vitamin B6, which was based on a lowest observed adverse effect level (LOAEL) of 100 mg/day found in one randomised controlled trial. VKM recognises that there are no well-designed dose-response studies of long-term use available. However, for adults, no adverse effects have been reported at doses with vitamin B6 up to 25 mg/day. Dietary calculations have been performed for mean intakes and in various percentiles (P5, P25, P50, P75 and P95) in children (2-, 4- and 9-year-olds), adolescents (13-year-olds) and in adults. To illustrate the consequences of amending the maximum limit for vitamin B6 in food supplements to 2, 6, 8, 10, 20 or 25 mg/day in the different age groups, VKM has used the scenarios with P95 from food and added the alternative amounts of supplements. VKM has compared these scenarios with the tolerable upper intake levels set by the Scientific Committee for Food in 2000 for adults, adolescents and children. In these scenarios, the 2- and 4-year-old children will exceed the tolerable upper intake level with use of 6 mg/day or higher vitamin B6 in supplements. The 9-year-old children will exceed the tolerable upper intake level with supplemental use of 10 mg/day. The 13-year-old adolescents will exceed the tolerable upper intake level with 20 mg/day of vitamin B6 in supplements. Adults will exceed the tolerable upper intake level with use of 25 mg/day of vitamin B6/pyridoxine in supplements.

Assessment of Vitamin E Intake in Relation to Tolerable Upper Intake Levels

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the intake of vitamin E (alpha-tocopherol) in the Norwegian population in relation to tolerable upper intake levels (ULs). The existing maximum limit for vitamin E in food supplements is 30 mg/day. VKM was also requested to conduct scenario calculations to illustrate the consequences of amending the maximum limit for alpha-tocopherol to 15, 50, 100, 150, 200 and 300 mg/day. Naturally vitamin E is a fat soluble compound synthesised by plants and consists of eight different tocopherols (α-, β-, γ- and δ- tocopherols and α-, β-, γ- and δ- tocotrienols) with varying vitamin E antioxidant activity. α-Tocopherol is recognised to meet human vitamin E requirements and accounts for 90% of the activity in human tissue. Vitamin E activity in food is expressed as α-tocopherol equivalents (α-TE) and 1 α-TE is defined as 1 mg d-αtocopherol. The physiological role of vitamin E is to react with free radicals in cell membranes and other lipid milieu, thereby preventing polyunsaturated fatty acids (PUFA) from being damaged by lipid peroxidation. This antioxidant activity is important to maintain membrane integrity and takes place in all cells in the body. Vitamin E deficiency symptoms include peripheral neuropathy, ataxia, myopathy and retinopathy. Vitamin E is dependent on lipid and lipoprotein metabolism and it takes decades for body depletion. The Norwegian recommended intakes for vitamin E for adults are 10 αTE/day for men and 8 α-TE/day for women. There is no evidence of adverse effects from the consumption of vitamin E naturally occurring in foods. Animal studies have shown that α-tocopherol is not mutagenic, carcinogenic or teratogenic. However, high doses of α-tocopherol supplements can cause haemorrhage and interrupt blood coagulation. VKM propose to adopt the tolerable upper intake level set by the Scientific Committee for Food Safety (SCF) which is based on one human dose-response study. Hence, the upper level for supplemental vitamin E is suggested to 300 mg/day for adults. The upper level for children and adolescents is derived from scaling the adult upper level based on body surface area (body weight 0.75). The tolerable upper intake levels set for vitamin E concern only intake from supplements, since intake of vitamin E from the diet is considered safe. VKM has therefore not conducted or evaluated scenarios with intake from both diet and supplements. Dietary calculations have, however, been performed for intake in various percentiles (P) P5, P25, mean, P50, P75 and P95 in children (2- 4- and 9-year-olds), adolescents (13-year-olds) and in adult men and women as background information. Mean and median intakes of vitamin E are above the recommended intakes for all age groups. No age group reaches the recommended intake at P5, and 9- and 13-year-old boys and 9-year-old girls do not reach the recommended intake at P25 from diet alone. Because the tolerable upper intake level for supplemental vitamin E for adults is 300 mg/day, none of the suggested amendments of the maximum limit in food supplements (to 15, 50, 100, 150, 200 and 300 mg/day) will lead to exceedance of this upper level in adults. In 13year-olds supplements with 300 mg/day vitamin E will lead to exceedance of the upper level. In 9-year-olds supplements with 200 mg/day vitamin E will lead to exceedance of the upper level. In 4- and 2-year-olds supplements with 150 mg/day vitamin E will lead to exceedance of the upper level. Vitamin E intake from fortified products is not included in the calculations, but are however, evaluated to be very low.

Assessment of Zinc Intake in Relation to Tolerable Upper Intake Levels

The Norwegian Food Safety Authority (NFSA, Mattilsynet) has requested the Norwegian Scientific Committee for Food Safety (VKM) to assess the intake of iron zinc in the Norwegian population in relation to tolerable upper intake levels (ULs). The existing maximum limit for zinc in food supplements is 25 mg/day. VKM has also conducted scenario calculations to illustrate the consequences of amending the maximum limit to 1, 2, 5, 10, 15 or 20 mg/day. Zinc is an essential trace element required for RNA, DNA and protein synthesis, cellular division, differentiation and growth (Mac Donald, 2000). Zinc is required for catalytic function in several enzymes and participates in all major biochemical pathways in the body. The function of the immune system depends on the ability of its cells to proliferate and differentiate, which is impaired in individuals with suboptimal zinc status (Barton et al. 2000). Due to its role in cell division and differentiation, adequate zinc nutrition is particularly important in children, and the requirements per kg body weight are highest in early life. The endogenous intestinal losses can vary from 7 mmol/day (0.5 mg/day) to more than 45 mmol/day (3 mg/day), depending on zinc intake (King and Turnlund, 1989). The requirements for zinc vary according to age and bioavailability. Several bioactive compounds in food such as tannins and phytic acids interact with zinc absorption and increase zinc requirements. The requirements vary twenty-fold according to life stage and diet. Zinc supplements, even at or slightly above the recommended intakes, can cause nausea and vomiting. The main concern with chronic zinc excess is, however, copper deficiency which is associated with several chronical illnesses. However, copper deficiency is uncommon due to the ubiquitous presence of copper in the diet. VKM proposes to use the ULs set by IOM (2001) as they provide values also for children and adolescents. The tolerable upper intake level set for adults is 40 mg zinc per day from food (and water) and supplements. Based on the scenario estimations, a dietary zinc intake at the 95th percentile and additionally 20 mg zinc from food supplements will lead to an intake close to the tolerable upper intake level established by IOM for adults. For adolescents and child populations the maximum amounts are 15 and 5 mg for 13- and 9-year-olds, respectively. For 2 and 4-yearolds, P95 from intake of zinc from food alone exceeds the UL.