Are there any kids with rickets in the u.s. nowadays?

Hard to find: Rickets requires a deficiency of vitamin D to extremely low levels. The usual RDA of 400 u per is designed to totally prevent this condition and vit D is usually added to milk. I imagine there are a few kids somewhere in the USA with extreme diets (enforced by well meaning parents) or with severe malabsorption problems who might have the condition. But I have not heard of them yet.

Unusual but there still are. Rickets due to nutritional vitamin D deficiency (low intake or malabsorption) in infants or children is rare. However, rickets in premature infants secondary to low intake of calcium or phosphorus is still observed, uncommonly though. There are other unusual cases of rickets related to metabolic diseases or chronic renal failure.