Local data

Lecture by Prof. Wing Hung Tam during the HKNA x WNSC HK Online Symposium 2021 highlighting latest dietary data including iron, iodine and vitamin D among local pregnant women and the potential health impact of microbiome.

The second territory-wide food consumption survey was performed in Hong Kong from 2018 to 2021 to understand food consumption information among Hong Kong adults (≥ 18 years). Two 24-hour dietary recall interviews were conducted for each respondent and food consumption information of selected food items was also collected using “food frequency questionnaire”. Some basic anthropometric and demographic information of respondents were also recorded. A total of 3,752 respondents have completed the survey and some key findings are listed below: Cereals and grains were consumed in the amount of 395.31 g daily with 61.2% (242.12 g/day) from rice subgroup Fruits and vegetables were consumed in the amount of 120.31 g/day and 202.65 g/day respectively Over half of the daily vegetable consumed were leafy vegetables and brassica vegetables Meat and poultry were consumed in the amount of 78.36 g/day and 32.12 g/day respectively Approximately 70% of the consumed meat was from pig other than offal Dim sum was consumed in the amount of 48.05 g daily Overall average body mass index (BMI) for male and female respondents was 24.07 and 23.01 respectively, higher than the corresponding values in the First Food Consumption Survey published in 2010 (overall average BMI of males and females is 23.7 and 22.7 respectively)

The Department of Health has commissioned the Chinese University of Hong Kong to conduct a survey on iodine, aiming to evaluate iodine status among local school-aged children (n = 1,023), pregnant (n = 1,513) and lactating (n = 482) women. Questionnaire interviews and spot urine iodine tests were performed for all subjects whereas thyroid ultrasonography was done for school-aged children. Key findings are listed below: School-aged children Median urinary iodine concentration (UIC) was 115 mcg/L (classified as “adequate” iodine intake as per the cut-off points recommended in the WHO’s Guide) Total goitre rate assessed with body surface area-specific reference values and age-specific reference values (1.7% and 2.2% respectively) were within the category of “none” degree for iodine deficiency as per the prevalence of goitre by WHO   Pregnant women Median UIC was 134 mcg/L (classified as “insufficient” iodine intake*) Median UIC of women taking iodine-containing supplements at an average daily iodine intake of at least 150 mcg/day was 156 mcg/L (classified as “adequate” iodine intake*)   Lactating women Median UIC was 65 mcg/L (classified as “insufficient” iodine intake*) Median UIC of lactating women taking iodine-containing supplements at an average daily iodine intake of at least 150 mcg/day was 84 mcg/L (classified as “insufficient” iodine intake*)   * According to the WHO classification

Iron deficiency is common over the globe and at-risk populations include pregnant women and young children. A local study including 97 mother-infant dyads examined how prenatal iron level impacts ferritin level in early infancy: Maternal iron deficiency (defined as serum ferritin level < 30 mcg/L) is common Noted in 56% of mothers upon delivery Only 3 infants showed iron deficiency (defined as serum ferritin level < 12 mcg/L) at 3 months of age No infant predominantly fed with formula had iron deficiency Cord blood serum ferritin levels were significantly higher than maternal ferritin levels, 148.9 ± 53.4 mcg/L vs 36.4 ± 35.9 mcg/L) No significant association between maternal ferritin levels with cord blood serum ferritin levels (r = 0.168; p = 0.108) nor with infant ferritin levels at 3 months (r = 0.023; p = 0.828) Infants ferritin levels at 3 months of age were independently related to cord blood serum ferritin levels (p = 0.007) and birth weight (p = 0.001) after adjustment