Assessment of Heavy Metals and Trace Elements in the Human Milk of Women Living in Latvia and an Evaluation of Influencing Factors.

During lactation, heavy metals and trace elements can be mobilised from the maternal body stores and excreted via human milk. A total of 66 mature human milk samples were collected from lactating women in Latvia between 2016 and 2017 to analyse the content of As, Cd, Pb, Al, Sn, and Ni. Additionally, 50 mature human milk samples were collected between 2022 and 2023 to analyse the content of Cd and Pb. The content of heavy metals and trace elements in human milk was determined using ICP-MS. Only two individual human milk samples contained heavy metals above the method's detection limit-one with an arsenic content of 0.009 mg kg-1 and one with a lead content of 0.047 mg kg-1. The preliminary data show that human milk among lactating women in Latvia contains only insignificant amounts of heavy metals and trace elements. Concern over such content should not be a reason to choose formula feeding over breastfeeding. Nevertheless, heavy metals, trace elements and other pollutants in human milk should be continuously monitored.

Mineral and Vitamin Intakes of Latvian Women during Lactation Period.

Studies from Europe and the United States indicate that women during the lactation period do not consume sufficient amounts of essential micronutrients. Previously reported data from Latvia indicates a low vegetable, fruit, fish, cereal, and milk and dairy products intake among lactating women. This raises concerns that nutrient (especially minerals and vitamins) intakes could also be insufficient. Therefore, this study aimed to assess mineral and vitamin intakes among lactating women in Latvia in comparison to nutritional guidelines at both a national and European level. 72-h food diaries were collected from 62 participants during the period November 2016 till December 2017 and from 68 participants during the period from January 2020 to December 2020. This also allowed us to evaluate whether nutrient intakes among lactating women in Latvia have changed in recent years. The Fineli Food Composition Database was used to calculate micronutrient intakes among the participants. MS Excel 2019 and IBM SPSS Statistics 23 were used for the statistical data analysis. The results revealed that dietary intakes of calcium, iron, iodine, and vitamins A, D, B1, and B9 among the participants of both study periods did not meet dietary recommendations. Low mineral and vitamin intakes could potentially affect the composition of human milk, and therefore micronutrient intakes, for breastfed infants. This indicates a need to develop dietary guidelines in order to improve diets among lactating women in Latvia.

Trans Fatty Acids in Human Milk in Latvia: Association with Dietary Habits during the Lactation Period.

The human milk fatty acid, including trans fatty acid, composition is predominantly affected by the maternal diet. The aim of this research was to determine the trans fatty acid level in human milk among lactating women in Latvia, and to evaluate how maternal dietary habits affect the trans fatty acid composition of human milk. In total, 70 lactating women participated in this cross-sectional study. A 72-hour food diary and food frequency questionnaire were used to evaluate maternal dietary habits. Different trans fatty acids in human milk samples were determined using gas chromatography (Agilent 6890N, Agilent Technologies Incorporated, the United States). Overall, the dietary intake of trans fatty acids among the participants was 0.54 ± 0.79 g per day. The total trans fatty acid level in the human milk samples was 2.30% ± 0.60%. The composition of trans fatty acids found in human milk was associated with maternal dietary habits. Higher elaidic acid, vaccenic acid and total trans fatty acid levels in human milk were found among participants with a higher milk and dairy product intake. Meat and meat product intake were associated with a higher vaccenic acid and total trans fatty acid levels in human milk. A moderate association was also established between maternal trans fatty acid intake and the total trans fatty acid level in human milk. The obtained correlations indicate that maternal dietary habits during lactation can impact the composition of trans fatty acids found in human milk.