The former Spice Girl stepped out at the United Nations' building in New York to accept her certificate from the Executive Director of Joint UN Programme on HIV/AIDS, Michel Sidibe.
"I am mother and I am a woman," she told the audience in a rousing speech. "I will do whatever I can to raise awareness.
Victoria missed the opening of her flagship store to go to New York for the ceremony
"I feel very passionate about this. I recently visited South Africa and was so touched by the women I met and felt inspired. I came home and I knew I had to do something.
"It's taken me to get to 40 to realise I have a responsibility as a woman and as a mother," she added. "I have people mentoring me. I am going back to South Africa in a few weeks and then further afield next year.
"I would do anything for my children," she said in reference to her three sons, Brooklyn, Romeo and Cruz and her daughter Harper. "And I think every woman has the right to health and every woman has the right to give their children a healthy future."
Victoria said she was inspired by her trip to South Africa
Meanwhile in London, fashion designer Victoria's flagship clothes store opened on Mayfair's Dover Street.
While Victoria couldn't attend the opening herself, her husband David Beckham paid a visit to the luxury shop as did her parents, Tony and Sandra Adams and her sister Louise.