Is a milk by any other name just as nutritious?
Vitamin D is an essential nutrient that supports healthy bones, muscles, and more, yet more than 90% of Americans don’t get enough in their diets. This is partly due to the fact that naturally occurring vitamin D is not found in high amounts in many foods, save for fish – a food which Americans certainly do not to eat enough of (see: every article ever posted on Talking Nutrition about Omega-3’s). As a result, vitamin D intakes in the United States are largely driven by fortified foods and dietary supplements, with the main fortification target being milk and dairy foods. Alternative milk sources such as soy and almond milk are becoming increasingly popular, and yet these aren’t always fortified with vitamin D. So that begs the question – what happens to the vitamin D status of regular drinkers of alternative (that is, non-cow) milks?
Lee et al. examined the relationship between consumption of these alternative milks and vitamin D status in a group of young Canadian children, 1 to 6 years of age. They found a significant inverse association between the amount of non-cow’s milk consumed daily and the vitamin D status (i.e., blood concentration) of the children – in other words, higher alternative milk consumption was associated with a lower vitamin D status.
What does this tell us? One way to interpret this study would be to say “avoid all alternative milks!” and call it a day. Seems logical based on the data, right? But I don’t know if that’s the right answer – instead I think that these data reinforce the important role that nutrient fortification plays in determining our nutrient intake as well as nutrient status. Vitamin D intakes from food are frequently observed to be low, and due to the high prevalence of inadequate intake as well as the significant health impacts that vitamin D deficiency can have, the 2010 Dietary Guidelines listed vitamin D as a “Nutrient of Public Health Concern” for American adults and children. Fortification with vitamin D helps to reduce the prevalence of nutritional inadequacy in both children and adults.
So really, the smart consumer should look at these data and say “I’m going to look for foods that are excellent sources of vitamin D” – no matter whether they come from naturally occurring sources like fish, sources like fortified cow’s milk or alternative fortified sources like soy or almond milks. If you choose vitamin D fortified dairy, great! If you choose to drink alternative milk sources, look at the nutrient facts panel to make sure they have vitamin D inside. There’s plenty of fortified options available, so be sure to choose them.
Moral of the study: judge your foods by their (nutritional) content – don’t be distracted by the name.
Lee GJ, et al. Consumption of non-cow’s milk beverages and serum vitamin D levels in early childhood. CMAJ 2014; epub ahead of print.
Berner LA, et al. Fortified foods are major contributors to nutrient intakes in diets of US children and adolescents. J Acad Nutr Diet 2014; 114(7): 1009-1022.
Fulgoni VL III, et al. Foods, fortificants, and supplements: where do Americans get their nutrients? J Nutr 2011; 141(10): 1847-1854.
Usual Intake of Total Fish & Other Seafood. Applied Research Program Web site. National Cancer Institute. http://appliedresearch.cancer.gov/diet/usualintakes/pop/2001-04/fish_all.html. Updated April 2, 2014. Accessed October 22, 2014.