How much vitamin d in milk
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Vitamin D Content in Milk: An Overview
Vitamin D Fortification in Retail Milk
Retail milk in the United States is commonly fortified with vitamin D to help prevent deficiencies in the population. The standard fortification level is 400 IU (10 µg) per quart, which translates to 25% of the daily value per 8 fluid ounces (236.6 mL) serving 1. However, the actual vitamin D content in milk can vary significantly. A study analyzing 120 milk samples found that only 49% of the samples contained vitamin D within 100 to 125% of the labeled amount. Some samples had as much as 800 IU (20 µg) per quart, while others had undetectable levels 1.
Variability in Vitamin D Content
The variability in vitamin D content in milk is a significant concern. In a study of 42 milk samples from 13 brands, only 29% contained 80 to 120% of the labeled vitamin D amount. A majority of the samples (62%) contained less than 80% of the stated amount, and some samples had no detectable vitamin D 3. This inconsistency highlights the need for better monitoring and regulation of vitamin D fortification in milk 34.
Vitamin D in Human Milk
Human milk naturally contains vitamin D, but the levels are relatively low. Studies have shown that human milk contains approximately 40 to 50 IU/L of vitamin D activity, primarily from 25-hydroxyvitamin D3, which accounts for about 75% of the total vitamin D activity 26. This amount is insufficient to meet the daily vitamin D requirements of exclusively breastfed infants, who receive less than 20% of the recommended daily dose from breast milk alone 6.
Vitamin D in Cow's Milk
Cow's milk naturally contains about 40 IU/L of vitamin D activity. This includes various vitamin D metabolites such as cholecalciferol and 25-hydroxycholecalciferol, which together account for the majority of the vitamin D activity in cow's milk 5. However, the vitamin D content can be influenced by the cow's diet, with higher dietary vitamin D intake leading to increased levels in the milk 5.
Fortification and Health Implications
Fortification of milk with vitamin D has played a crucial role in preventing rickets in children and osteomalacia in adults. However, improper fortification can lead to health issues. For instance, an outbreak of vitamin D intoxication was linked to milk that was excessively fortified, with some samples containing up to 232,565 IU per quart 9. This underscores the importance of accurate fortification and regular monitoring to ensure safety and efficacy 9.
Conclusion
The vitamin D content in milk, whether naturally occurring or through fortification, varies widely. While fortification has been effective in preventing vitamin D deficiencies, inconsistencies in the actual vitamin D levels in retail milk highlight the need for stringent monitoring and regulation. Both underfortification and overfortification pose health risks, making it essential to maintain accurate fortification practices to ensure public health safety.
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Most relevant research papers on this topic
Vitamin D content and variability in fluid milks from a US Department of Agriculture nationwide sampling to update values in the National Nutrient Database for Standard Reference.
Vitamin D content in retail milk varied widely, with 49% of samples within 100 to 125% of the label value, and 2% milk having higher vitamin D levels in 2007 compared to 2001.
Highly CitedVitamin D of human milk: identification of biologically active forms.
Human milk contains 25-hydroxyvitamin D3, which accounts for over 90% of the total vitamin D activity, indicating that unknown metabolites do not provide significant vitamin D activity.
In Vitro StudyHighly CitedThe vitamin D content of fortified milk and infant formula
Milk and infant formula rarely contain the amount of vitamin D stated on the label, suggesting a need for better monitoring of the fortification process.
Highly CitedAn update on the vitamin D content of fortified milk from the United States and Canada.
Fortified milk in the United States and Canada contains 80 to 120 percent of the vitamin D claimed on the label, with 71 percent of samples not meeting this target.
Highly CitedVitamin D compounds in cows' milk.
There is no evidence for the existence of a highly active water-soluble form of vitamin D in cow's milk.
Non-RCT
Animal StudyVitamin D content in human breast milk: a 9-mo follow-up study.
During the first year of life, exclusively breastfed infants received 20% of the daily recommended dose of vitamin D from breast milk.
Observational Study
Very Rigorous JournalHighly CitedThe total content of vitamin D in human milk and cow's milk
Whole cow's milk and human milk contain significantly lower levels of vitamin D compared to previously reported values, suggesting that their antirachitic activity on rats is insufficient for human consumption.
Non-RCTAnimal StudyHighly CitedThe Vitamin D Content of Fortified Milk and Infant Formula
Most fortified milk and infant formula samples tested did not contain 80 to 120 percent of the vitamin D stated on the label, with no vitamin D detected in 3 out of 14 skim milk samples.
Highly CitedHypervitaminosis D associated with drinking milk.
Drinking milk that is incorrectly or excessively fortified with vitamin D may result in hypervitaminosis D, requiring careful monitoring.
Case ReportHighly CitedEfficacy of Daily Supplementation of Milk Fortified With Vitamin D2 for Three Months in Healthy School Children: A Randomized Placebo Controlled Trial
Daily supplementation of milk fortified with 240 IU vitamin D2 for three months did not achieve sufficient serum 25(OH)D levels in Indian children with vitamin D deficiency during winter.
RCT