Recommending a vitamin D supplement from the first week of life for susceptible infants who are breastfed is safe, effective and, therefore, should be considered. A vitamin D supplement is critically important for those in the inner city and those with increased skin pigmentation. Because this method requires daily treatment, success depends upon compliance. An alternative and recommended therapy is to administer the vitamin D in a single day, usually divided into 4 or 6 oral doses. An intramuscular injection also is available.
Vitamin D is well stored in the body and released gradually over many weeks.
Neither calcitriol nor calcidiol with their short half-lives are suitable. In nutritional rickets, the phosphate level rises in 96 hours and radiographic healing will be visible in 6-7 days. One must be careful in the single-day regimen not to use a preparation of vitamin D suspended in propylene glycol. At this dosage, the vehicle is toxic. One may use 50,000 U capsules of ergosterol, softened in water and fed with a blended food such as applesauce.