Breastfeeding Hong Kong mums not getting enough calcium, iron and iodine, study finds
But their babies’ intake levels were found to be adequate
Breastfeeding mothers in Hong Kong are not getting enough calcium, iron and iodine, researchers said, warning the deficiencies could adversely affect their health over the long term.
But the study by Polytechnic University’s Laboratory for Infant and Child Nutrition, involving 95 lactating women between May 2014 and August last year and including a three-day diet survey, found the babies’ intake levels were adequate.
The study revealed that only 12 per cent, 6 per cent and 2 per cent of the participanting women met the recommended intakes of calcium, iron and iodine respectively, based on the Chinese Dietary Reference Intakes, which are compiled by the non-profit Chinese Nutrition Society and recognised by government authorities.
Professor Wong Man-sau of PolyU’s department of applied biology and chemical technology noted the daily intakes of the micronutrients were “significantly lower” than what was recommended for lactating women: 1,000mg of calcium, 24mg of iron and 240mcg of iodine.
Registered dietician Gordon Cheung Chi-leung saidbreastfeeding women needed higher intakes of such micronutrients for their health and breast milk production.
Cheung said the findings were “concerning”, as the participants’ median daily intake of the micronutrients were only 700.6mg per day, 13.27mg per day and 44.9mcg per day for calcium, iron and iodine respectively.
The study also looked at the breast milk samples of 39 women who had been lactating between zero and six months.
It found that 51 per cent of breast milk samples had adequate calcium levels for their babies as recommended by Chinese Dietary Reference Intakes. Results were better for iron, with 74 per cent of the samples reaching adequate levels. But only 48 per cent of the samples had enough iodine.
The findings came despite the much lower levels of micronutrient intakes for the mother.
Babies usually receive enough calcium, iron and iodine from breast milk, Cheung explained, but “mothers suffer from a depletion of body reserves of such micronutrients”.
He added the mothers’ inadequate intake could lead to osteoporosis, iron deficiency anaemia and hypothyroidism.
Cheung recommended lactating mothers consume a wide variety of food, such as dairy products and dark green vegetables, which are sources for calcium, meat and poultry. He likewise recommended beans and nuts, which are rich in iron, as well as seafood and seaweed, which contain iodine.
A woman surnamed To said her iodine level was low when she took part in the study.
She said she did not know at the time that she should have been consuming food such as seaweed and seafood during her lactation period to get iodine. She added she abstained from such foods due to traditional Chinese dietary beliefs that they are not good for breastfeeding women.