The most important thing is to include a wide variety of fresh, healthy foods in your breastfeeding diet.
If you think something you're eating is affecting your baby through your breast milk, talk to your GP or health visitor, or call the National Breastfeeding Helpline on 0300 100 0212.
Vitamin D is found in certain foods (including oily fish like salmon, sardines, and mackerel; red meat; and some breakfast cereals) but it's hard to get enough from food alone. It's sometimes referred to as the 'sunshine vitamin' as we get most of our vitamin D from sunlight (from late March to the end of September).
If you're breastfeeding, you should consider taking a vitamin D supplement (containing 10mcg).
If your baby is only having breast milk (no first infant formula top-ups), you should give them a daily vitamin D supplement of 8.5 to 10mcg.
It's worth checking if you're entitled to Healthy Start food and vitamin vouchers. If you're not, ask your GP or health visitor where to buy them.