My dear, I am very concerned. Did you baby get an injection of vitamin K at birth? The baby should be on 400 IU of vitamin D per day delivered via drops prescribed by
pediatrician. You, my dear, are another situation. You were given injections that contained about 60,000IU of vitamin D and that is usually given when you have osteomalacea and/or are severely deficient in D.
Getting enough vitamin D just be sunlight is difficult and depends on your geographical location.
For the health of the baby, you need to optimize your health. The baby is getting its nutrients from you and if you are deficient so is your baby. I suggest you and your infant be tested for D levels before anything is done.
You will need to take a vitamin D supplement of some strength to build your blood level up. Now, in a nutritional clinic I would recommend 5,000IU per day, but the doctor may take a look at your test results and recommend something totally different.
Vitamin D is difficult to obtain from the diet, but fatty fish, fortified milk, fortified cereals are sources of vitamin D.
Please, get testing for adequate recommendations for repletion if needed.
You also need to assure you have adequate calcium. Many mothers continue to take their prenatals while
breastfeeding.