Government workers started distributing 1 million baht's (USD 28,600) worth of prenatal vitamins today to women between the ages of 20 and 34.
The pills contain folic acid and iron.
The giveaway is part of a program called "the campaign for red-cheeked Thai women to have children for the country using very magical vitamins."
Fewer Thai couples are getting married, and are doing so later in their lives, meaning fewer children each year.
More From This Section
Thailand's population grew by only 0.4 per cent in 2015, down from 2.7 per cent in 1970. If the trend continues, the population will stop growing in 10 years, Wachira said.
The campaign is also hosting wedding ceremonies as Thais consider Valentine's Day to be an auspicious day to get married.
Worrawut Ploywong and Priyapat Ploywong were among the couples tying the knot today.
"As for having babies, I want to have them as soon as we can and as many as we can," said Worrawut, a wing commander in the Thai air force. "We wish for many souls to be born.