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Vitamin D in Human Milk

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Human milk provides 3 units of vitamin D per 100 grams, but this will depend on the reserves of the breastfeeding or chestfeeding person. However, the main source for the synthesis of vitamin D is exposure to the sun, but due to our current habits, the risks of sun exposure, limited outdoor activity, especially in countries or regions with cold temperatures, our sun exposure is not sufficient to produce this important vitamin. Additionally, there are few foods rich in vitamin D, and most of them are fortified. The Institute of Medicine considers 20-30 ng/ml to be adequate for the majority of the population.


Why is this vitamin so important?


Vitamin D helps the body properly control calcium and phosphorus levels. This, in turn, prevents malformations, rickets, seizures, and dyspnea (breathing difficulty or shortness of breath). In addition, vitamin D plays an important role in our immune system.


That's why many pediatricians recommend vitamin D supplementation for infants.

The American Academy of Pediatrics recommends supplementing with 400 units per day of vitamin D to prevent rickets or supplementation of 6400 IU for the breastfeeding or chestfeeding person.


Supplementing the baby can be inconvenient as many babies refuse to take it, and mixing it with human milk for those who breastfeed or chestfeed directly from the breast or chest can be inconvenient. For this reason, it is also recommended that the breastfeeding or chestfeeding person take a supplement of 6400 IU per day of vitamin D to meet both her nutritional requirements and those of her baby.


Even when the levels of vitamin D in the blood of the breastfeeding or chestfeeding person are in the "normal" range, this does not guarantee that human milk will contain sufficient vitamin D because they are two different compounds. The blood test measures the level of the active metabolite 25(OH)D, but vitamin D is the one that passes into human milk, so the only way to be certain is to take it as a supplement daily.

In conclusion, human milk contains vitamin D, but this will depend on the reserves, diet, or sun exposure of the breastfeeding or chestfeeding person.



Vitamin D for Babies, Children & Adolescents -

Maternal Versus Infant Vitamin D Supplementation During Lactation: A Randomized Controlled Trial | Pediatrics | American Academy of Pediatrics (

Summary - Dietary Reference Intakes for Calcium and Vitamin D - NCBI Bookshelf (

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