%0 Journal Article
%T Natural history of infants with vitamin D deficiency in Hong Kong.
%A Tung JY
%A So HK
%A Tung KT
%A Wong RS
%A Tsang HW
%A Chan B
%A Tso WW
%A Wong IC
%A Yam JC
%A Lee SL
%A Pang G
%A Wong WH
%A Cheung KW
%A Leung WC
%A Ip P
%J Asia Pac J Clin Nutr
%V 32
%N 4
%D 2023 Dec
%M 38135475
%F 1.322
%R 10.6133/apjcn.202312_32(4).0004
%X <B>OBJECTIVE: </B>The usual recommended intake of vitamin D for healthy infants is 400 international unit (IU) daily. However, a high dose of vitamin D at 2000-3000 IU daily is needed for those with vitamin D deficiency (VDD). This study aimed to assess the natural history of a group of healthy infants with VDD and the associated factors for persistent VDD.<BR><B>METHODS: </B>Healthy infants detected to have VDD (25OHD <25 nmol/L) in a population study were followed, and their demographics and clinical data were collected.<BR><B>RESULTS: </B>One hundred and thirty-one subjects (boys = 66%) were included. Their first serum 25OHD was taken at a median age of 87.5 days. None were treated with high-dose vitamin D supplements, but some have been given vitamin D at 400 IU daily. They were assessed again at the median age of 252.5 days when 15 remained to have VDD and 26 were in the insufficient range (25 - 49.9nmol/L). All persistent VDD children were on exclusive breastfeeding. Exclusive breastfeeding and no vitamin D supplementation were significant risk factors for persistent vitamin D insufficiency (<50nmol/L).<BR><B>CONCLUSIONS: </B>Persistent VDD is common among infants exclusively breastfeeding and those who did not receive vitamin D supplementation.