"Extra vitamins" refers to additional nutrients that our bodies need to stay healthy and strong. These vitamins help us fight off illnesses, have more energy, and support the growth and development of our bodies. Full definition
These extract capsules boast the same health benefits as eating the fruit itself, including providing the consumer with extra vitamin C to help against inflammation. (herbazest.com)
If none of those options are available to you then it is best to take extra vitamin D supplements or to increase the vitamin D you get through food. (supernaturalacnetreatment.com)
They do likely need extra vitamin D though if they are breastfeeding and not getting vitamin D from another source. (verywellfamily.com)