While you can probably meet all of your recommended nutrient levels through diet alone while nursing, taking vitamin supplements can add to your peace of mind. Understanding which vitamins and minerals you might need during breastfeeding can help you decide if you need to take vitamin supplements to complement your healthy diet.
Continuing prenatal vitamins while breastfeeding is not necessary, but it is an easy way to ensure that you are continuing to get adequate levels of the vitamins and minerals you and your baby need. Don't take more than you took during pregnancy, however, and don't add other supplements during breastfeeding unless directed by a doctor. Water-soluble vitamins, such as vitamin C, do not increase past a safe dose in breast milk even if the mother takes excessive amounts, but fat-soluble vitamins, such as vitamin A, can build up to dangerous levels in breast milk if taken in excess by the mother.
In general, a mother's body supplies her breastfeeding infant with the nutrition he needs by taking it from her own stores if necessary. Because of this, it is rare for a nursing infant to develop a deficiency without his mother first developing a deficiency. One exception may be vitamin D, which is produced by the skin during time spent in the sun. Babies and mothers who do not spend time in the sun may need supplemental vitamin D, given either to the mother or baby. A mother who takes supplemental vitamin D can pass this vitamin to the baby through breast milk. Strict vegans who are breastfeeding may also need to supplement with vitamin B12. This nutrient is most readily available from animal sources, so a vegan lactating mother likely does not get enough through diet to supply her infant.
Most vitamins are not depleted by nursing, but some of the essential minerals in your diet may be. A nursing woman needs 1,000 mg of calcium, not for the baby but for herself. Calcium leaves the bones during breastfeeding and the calcium a mother takes in replaces the loss. If you aren't drinking three cups of milk a day, or consuming the equivalent in dairy or calcium-enriched foods and juices, you might want to take a calcium supplement. A nursing mother may also need zinc or iron if her own stores of these nutrients fall too low.
If you don't take a prenatal vitamin or other supplement, make sure to eat a well-balanced diet to get all of the nutrients you need. Consider taking a prenatal vitamin or supplements if your diet lacks one or more of the essential food groups. If you have concerns about your baby getting the nutrition she needs from your breast milk, talk to a doctor about supplementing your own diet instead of giving vitamins to the baby. Maternal supplementation can usually prevent any deficiencies a baby might be prone to developing.