Erkki Vuori

Breast milk iron--a declining concentration during the course of lactation.

Abstract. Siimes, M. A., Vuori E. and Kuiunen P. (Childrens Hospital and Department of Public Health Science, University of Helsinki, Helsinki, Finland). Breast milk iron—a declining concentration during the course of lactation. Acta Pædiatr Scand, 68: 29, 1979.—The present investigation is the first longitudinal study of the concentration of iron in breast milk and is based on 229 milk samples obtained from 27 mothers during their period of lactation up to 9 months. The samples were collected at the beginning and at the end of each feed during a 24‐h period to reflect as accurately as possible the actual concentration of iron. The median value declined during the course of lactation from 0.6 to 0.3 mg/l with a large range of values. The results indicate that the concentration is lower than is generally stated or is unusually low in Finnish mothers. As a consequence some infants may require iron supplementation during prolonged breast feeding although in general, the high bioavailability of breast milk iron prevents the development of iron deficiency.

The effect of washing procedures on trace element content of human hair

Abstract The effects of four washing procedures on the concentrations of manganese, iron, copper, zinc and cadmium and were investigated for three pooled samples of human head hair. The solutions evaluated were a non-ionic detergent (Triton X-100), an ionic detergent (sodium lauryl sulfate), acetone and a complexing agent (EDTA). The results indicate that for every element determined there is a level below which the concentration cannot be reduced by further washings. The numbers of washings required to reach these levels vary considerably. This effect must be considered in the trace element analysis of hair.

MATERNAL DIET AND FATTY ACID PATTERN OF BREAST MILK

ABSTRACT. The effect of habitual maternal diet on the fatty acid composition of breast milk was evaluated by conducting a dietary survey of lactating mothers and by analyzing their breast milk samples. The mean energy intake of the mothers was 9.8 MJ during the first survey week (20 mothers, 6‐8 weeks post partum) and 8.6 MJ during the second survey week (13 mothers, 17‐22 weeks post partum). Protein, fat and carbohydrate intake comprised 16%, 39% and 45% of the total energy intake, respectively. The breast milk samples contained 3.8% fat. Half of the fatty acids of the diets and breast milk were saturated (S), and one third were monoenoic. Polyunsaturated (P) fatty acids comprised 15% in the diets and 13% in the breast milk. The average P/S ratio was 0.3 both in the diets and breast milk samples. Carbohydrate intake correlated negatively (p<0.05) with arachidic acid of breast milk, and both protein and fat intakes correlated positively (p<0.05) with palmitic acid of breast milk. The maternal diet had no effect on the total fat content of breast milk. A positive correlation was found between the saturated (p<0.05) and polyunsaturated (p<0.01) fatty adds of maternal diet and breast milk. As to the single fatty acids, the only significant correlation was found with linoleic acid (p<0.01). However, the variation of linoleic acid intake explained only about 27% of the variation occurring in the breast milk.

Intake of copper, iron, manganese and zinc by healthy, exclusively-breast-fed infants during the first 3 months of life

1. The calculated median daily trace element intakes /kg of exclusively-breast-fed infants at 1, 2 and 3 months of age respectively were: copper 0.075, 0.051 and 0.043 mg; iron 0.075, 0.055 and 0.048 mg; manganese 0.9, 0.6 and 0.5 microgram; zinc 0.420, 0.215 and 0.150 mg. The latter values for Cu, Fe, and Zn intakes were in good agreement with earlier results, whereas the intake of Mn was lower. The intakes of trace elements by breast-fed infants seemed to be below the recommended dietary allowances (Food and Nutrition Board, 1973; WHO Expert Committee on Trace Elements in Human Nutrition, 1973). 2. There seems to be no information on trace element concentrations of breast milk related to the energy content. Such values are therefore included for breast milk from Finnish women for the 1st 6 months of lactation.

Dietary chromium intake of lactating Finnish mothers: effect on the Cr content of their breast milk.

1. The chromium in the diets of lactating Finnish mothers and of their breast milk was determined by graphite furnace atomic absorption. 2. The average maternal diet was estimated to provide approximately 30 micrograms Cr/d. Breast milk samples has a mean Cr content of 0.4 ng/ml, with a range of 0.19-0.69 ng/ml. 3. Cr intake of the lactating mothers did not correlate with the corresponding breast milk Cr concentration. 4. The diets and the breast milk of these Finnish mothers were lower in Cr than those of any other population studied in the world.

Biologically active metals in human tissues. I. The effect of age and sex on the concentration of copper in aorta, heart, kidney, liver, lung, pancreas and skeletal muscle.

Autopsy specimens of aorta, heart, kidney, liver, lung, pancreas and skeletal muscle were collected from 86 accident victims. The copper concentration in each tissue was determined with atomic absorption spectrophotometry. The descending order of the tissues in respect to copper concentration was: liver, heart, kidney, pancreas, lung, muscle, and aorta. No significant difference was found in the copper levels of samples from male and female autopsies. When the effect of age on the average copper concentration was studied, liver and kidney showed a decreasing concentration up to maturity, the copper concentration in pancreas and skeletal muscle showed a continuous decline with increasing age, and there was no clear-cut effect of age on the copper concentration of heart, lung and aorta. According to the results the Finnish population does not differ, on the average, from other populations with respect to tissue copper concentrations.

Effect of maternal fluorine intake on breast milk fluorine content.

1. Breast milk samples were collected from mothers living in areas having an average of 0.2 and 1.7 microgram fluorine/ml in drinking water. The samples were analysed for their ionic and total F concentrations. 2. Ionic F was determined after microdiffusion by the fluoride-selective electrode. For total F determinations, milk samples were ashed with magnesium succinate fixative, after which the F concentration was determined as mentioned previously. 3. The median totals for F content of breast milk in the low- and high-F areas were 7.0 ng/ml (range 4.3-14.0 ng/ml, fifteen mothers) and 10.9 ng/ml (range 4.5-50.7 ng/ml, nine mothers). The median ionic F concentrations were 5.0 ng/ml (range 3.0-6.3 ng/ml, fifteen mothers) and 8.9 ng/ml (range less than 2.0-39.9 ng/ml, nine mothers) respectively. Both the total F (0.01 greater than P greater than 0.001) and ionic F (0.05 greater than P greater than 0.01) in breast milk were significantly higher in the high-F area compared to the low-F area. 4. At the ages of 1,2 and 3 months, the calculated average total daily F intakes of exclusively breast-fed infants were 4.8 and 7.3 microgram; 5.0 and 7.8 micrograms; 5.4 and 8.5 micrograms in the low- and high-F areas respectively.

The occurrence and origin of DDT in human milk.

Abstract. Gas chromatography has been applied for the analysis of organochlorine compounds of 49 samples of human milk. The average total DDT (2,2‐bis(4‐chlorophenyl)1,1,1‐trichloroethane) content in human milk was found to be 0.058 mg/kg, ranging from 0.017‐0.17 mg/kg (1.57 mg/kg milk fat, with a range of 0.50‐4.00 mg/kg). Thirty‐four cases contained traces of dieldrin, but the content of dieldrin reached 0.008 mg/kg in only one milk sample. The average content of PCB (polychlorinated biphenyls) was 0.024 mg/kg of human milk, with a range of 0.011‐0.054 mg/kg (0.65 mg/kg of milk fat with a range of 0.33‐1.10 mg/kg). The ratio of DDT metabolites/DDT varied from 1.1 to 7.8 (mean 2.8). Studies were also made of the effect of the weight, weight loss, diet, smoking habits and parity of the nursing mother upon the content of organochlorine compounds in human milk. A significant positive correlation was observed between the DDT content of human milk fat and cigarette smoking.

A longitudinal study of manganese in human milk.

Abstract. Flameless atomic absorption spectrophotometry has been applied to the analysis of manganese in human milk samples. Twenty‐seven breast‐feeding mothers donated 229 individual milk samples between the 2nd week and the 9th month of lactation. The milk samples were representative of every feed in a period of 24 hours, foremilk and hind‐milk in equal proportions. The median concentration of manganese declined from the initial value of 5.9 μg/l to about 4 μg/l before the 2nd month of lactation, remained at this level up to the 5th‐6th month of lactation and showed a tendency to rise thereafter. The values presented here are noticeably lower than most of those reported earlier. It remains an open question whether the manganese concentration is exceptionally low in Finnish human milk or whether the great difference from most earlier studies may reflect problems of contamination or technical difficulties when less sensitive analytical methods have been used.

Cadmium in Finnish breast milk, a longitudinal study.

Electrothermal atomic absorption spectrophotometry was employed to analyse cadmium in breast milk. Twenty breast milk samples were donated by seven mothers during 6 months of lactation. All milk samples represented every feeding during a period of 24 h, having foremilk an hindmilk in equal proportions. The median cadmium concentration in the 1st month was 2.0 μg/l (range 1.7–3.1 μg/l, 7 samples) and then declined to 1.5 μg/l (range 1.3–2.5 μg/l, 7 samples) and 1.6 μg/l (range 1.2–2.0 μg/l, 6 samples) in the 3rd and 6th months, respectively. At the age of 1 and 3 months when the infants were totally breast fed the average weekly intake of cadmium was 2.7 and 1.5 μg/kg. This is below the provisional tolerable weekly intake of man, from 6.7 to 8.3 μg/kg, proposed by WHO.