The daily dose of vitamin D advised for mothers during lactation are currently 400 IU/day. The authors say this dose is too low, especially for dark pigmented people. Rickets in infancy is an increasing problem in the breastfed children because of the current fear of the sun and of skin cancer. Vitamin D is converted to 25-(OH)D, a hormone, in the liver. This is converted to the active form, 1,25-(OH)D, by the kidney.
Light skinned people who have full body exposure to the sun for 10-15 minutes at peak times in the summer can produce as much as 20,000 IU of vitamin D per day. This is without sun screen.
The purpose of this study is to determine the proper dose of vitamin D to promote the health and nutritional status of mothers and their nursing infants. The results show that for pregnant mothers 2000 IU of vitamin D per day is an adequate dose and 4000 IU per day is an improved dose to prevent rickets in infants.
Mothers were given various doses of vitamin D and the antirachitic activity (25-hydroxyvitamin D) of the blood of the mothers and their nursing babies was determined. Without sun exposure and with 400 IU/day to the mothers, the babies could not sustain adequate levels of 25-(OH)D. At doses of 2000 IU/day, the children had increased levels of 25-(OH)D, although to a limited degree. The dose of 4000 IU/day to the mother, there was a marked improvement in the babies’ nutritional vitamin D status.
The authors gave people as much as 10 times the RDI (recommended daily intake) with no negative effect over 3 months. There was no hypercalciuria (calcium in the urine.)
CONCLUSION: Vitamin D is important to promote bone growth in infants and for preventing bone deterioration as humans age. Supplementation of milk with vitamin D nearly eliminated rickets in the 1930’s. But, the fear of the sun that has grown since that time has greatly reduced our bodies content of vitamin D, in general. The problem is especially acute for dark skinned populations and for people who wear sun block.
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