The percentage in Vietnam is much lower than Laos and Cambodia, with 40% and 65%, respectively. Thailand comes in at 12%.

The first 1,000 days are the "golden" period for providing critical nutrition to foster height and intelligence in infants, the UNICEF representative said.

Effective methods include nutrition supplements during pregnancy, breastfeeding exclusively in the six months, continuing breastfeeding and making sure infants get enough nutrition in the following months.