Manganese daily intake

The range of potato manganese content has been reported from 0.73-3. 62 p,g/g FW (Rivero etal., 2003) to 9-13 p,g/g DW (Orphanos, 1980). Manganese has a role in blood sugar regulation, metabolism, and thyroid hormone function. Recommended daily intake in the USA is 2-10 mg. 

J. P. Buchet, R. Lauwerys, A. Vandevoorde, J. M. Pycke, Oral daily intake of cadmium, lead, manganese, copper, chromium, mercury, calcium, zinc, and arsenic in Belgium duplicate meal study, Food Chem. Toxicol., 21 (1983), 19-24. 

Experiments In this laboratory examined the effects of small (100 and 300 mg) doses of sodium phytate administered In capsule form on plasma uptake of 50 mg of MnCl. As shown In Figure 5, the 300 mg dose of phytate produced a moderate reduction In manganese response, which was manifested chiefly at hours three and four of the test. The relatively modest effect of phytate on manganese uptake Is somewhat unexpected, since It has been shown that phytic acid may be a more potent Inhibitor of trace element absorption than dietary fibers (35). However, the doses of sodium phytate administered to our subjects were much smaller than the typical daily Intake of 600 to 800 mg (54). Thus we are now Investigating the effects of larger doses of phytate on manganese uptake. 

Calcium has long been suspected as adversely affecting the bioavailability of manganese. Excessive intakes of calcium or phosphorus have been shown to increase the daily requirements for manganese in swine (3-5) probably due to decreased absorption of this mineral. However, comparatively little information is available on the comparative effects of different sources of calcium on manganese utilization in humans. 

One study showed that, in full-term infants, manganese is absorbed from breast milk and cow s milk formulas that were either unsupplemented or supplemented with iron, copper, zinc, and iodine (Domer et al. 1989). Manganese intake was greater in the formula-fed infants than in the breast-fed infants due to the higher manganese content of the formula. However, breast-fed infants retained more of their daily intake of... 

MMT. The daily excretion of manganese from mice ingesting 11 mg manganese/kg as MMT in their daily diet was 5.4% of their daily intake (Komura and Sakamoto 1992). 

Data on the effects of manganese following chronic oral exposure are less extensive than those available on inhalation exposure and are not sufficient to derive a chronic oral MRL. However, the available literature reports do show that neurological effects similar to those seen after inhalation exposure may be anticipated following chronic oral exposure to levels above estimated daily intake. In most chronic oral studies examined (Holzgraefe et al 1986 Iwami et al. 1994 Kawamura et al. 1941 Kilburn 1987 Kondakis et al. 1989), there is uncertainty regarding the exposure level or whether the effects were solely attributable to manganese, so these studies are not suitable for the derivation of a chronic oral MRL value. 

Manganese is ubiquitous in the environment. It occurs in soil, air, water, and food. Thus, all humans are exposed to manganese, and manganese is a normal component of the human body. Food is usually the most important route of exposure for humans typical daily intakes range from 1-5 mg/day. 

Daily intake of manganese by the adult population of Mumbai. Sci Total Environ 250 43-50. 

Hunt CD and Meacham SL (2001) Aluminum, boron, calcium, copper, iron, magnesium, manganese, molybdenum, phosphorus, potassium, sodium, and zinc concentrations in common Western foods and estimated daily intakes by infants toddlers and male and female adolescents, adults, and seniors in the United States. J Am Diet Assoc 101 1058-1060. 

Recommended dietary allowances for a male adult (daily intake, in foods and food supplements) of some nutrients, usually the amounts estimated as needed to prevent overt manifestation of deficiency disease in most persons. For the substances listed in smaller amounts the optimum intake, leading to the best of health, may be somewhat greater. Not shown, but probably or possibly required, are the essential fatty acids, />aminobenzoic acid, choline, vitamin D, vitamin K, chromium, manganese, cobalt, nickel, zinc, selenium, molybdenum, vanadium, tin, and silicon. 

Manganese intake in average U.S. diet—In the United States, the normal daily intake of manganese varies from 2 to 9 mg/day in adults, depending on the composition of the diet. 

In 1941, Kent and McCance (25) measured balance in three subjects eating mixed diets containing 1.72, 2.21, and 6.64 mg Mn/day. In the first 7-day period measured, mean respective balances of-0.05, +0.16, and -0.39 mg Mn were found. In two other subjects, substitution of white for brown flour decreased the manganese intake from 8.67 to 2.45 mg/day and the daily balance from 0.26 to 0.02 mg. 

When 7-day diet composites were collected during the four seasons of the year, Patterson et al. (37) found a mean intake of 3.0 mg Mn/day and a nutrient density of 1.6 mg Mn/1000 kcal. Based on this figure, a consumption of 1560 kcal would be adequate to meet the lower limit of the suggested safe and adequate range (63). However, in Fig. 1 the theoretical point of equilibrium is 3.55 mg and it appears that approximately 5 mg is needed to consistently maintain positive balance. These would require a daily consumption of 2250 and 3125 Kcal, respectively. Thus, it seems plausible that some individuals may be at risk for being in negative manganese balance. 

Manganese is an essential nutrient for humans with a daily estimated adequate safe and daily dietary intake of 2.5 to 5.0 mg (1). Yet trace mineral nutriture depends not only upon dietary intake, but also upon availability for absorption. Currently, little is known regarding the influence of dietary factors on the absorption of manganese. Thus the intent of these studies was to (a) develop a test that would readily measure Mn bioavailability in humans and (b) utilize this test to determine the influences of various dietary factors on Mn bioavailability. 

When oral intake is precluded, the recommended daily parenteral supplementation of manganese is 0.15-0.8 mg. Manganese is mainly excreted in the bile during cholestasis serum manganese levels may rise, and manganese toxicity can result. Hjq)ermanganesemia after parenteral nutrition when first reported was linked to portosystemic encephalopathy. Patients with liver disease were particularly at risk. 

---