New research from St. Michael’s Hospital in Toronto, Canada suggests young kids who drink rice, almond soy or goat’s milk are at risk for vitamin D deficiency.
According to the study, published Oct. 20 in the Canadian Medical Association Journal, children who drink non-dairy beverages are more than twice as likely to have vitamin D levels inadequate to build strong bones compared to milk-only drinkers.
Vitamin D supports the normal development of bones and teeth by helping the body absorb calcium from foods and supplements. Too little vitamin D can lead to low calcium levels in the blood, causing the body to pull calcium from the bones to replace what’s missing in the bloodstream.
In young children, vitamin D deficiency can cause rickets, a condition causing the bones to become soft and weak and potentially leading to bone deformities. In older kids (as well as adolescents and adults), inadequate vitamin D can increase the risk of bone fractures.
Vitamin D also helps muscles contract, supports the immune system, reduces inflammation and may be important for heart health and, possibly, cancer prevention.
For the study, researchers looked at differences in blood levels of vitamin D associated with drinking cow’s milk and non-cow’s milk among 2,831 healthy children, aged one to six, living in Toronto. Among children who drank only non-dairy beverages, 11 per cent had a vitamin D level below what’s required for adequate bone health compared to 4.7 per cent of milk drinkers, even after accounting for factors that influence vitamin D levels such as body weight, vitamin D supplementation, use of margarine, skin colour and outdoor playtime.
Even milk drinkers in the study who also drank non-dairy beverages had lower levels of vitamin D than if they just stuck to drinking cow's milk.
These findings don’t mean that non-dairy beverages drain calcium from the body. Rather they suggest that substituting cow’s milk with milk alternatives that lack vitamin D, or are lower in vitamin D than milk, could put children at risk for complications of vitamin D deficiency.
In Canada and the United States, cow’s milk is required by law to be fortified with 100 IU (international units) of vitamin D per 250 ml. (The only other food with mandatory vitamin D fortification is margarine with 50 IU per two teaspoons.) Because milk fortification is legislated, the government monitors vitamin D content.
Fortification of plant-based beverages such as soy, rice, almond, hemp and coconut as well as goat’s milk, however, is voluntary. While many manufacturers do add vitamin D (100 IU per 250 ml) to their products – along with calcium, B12 and other nutrients – not all do.
Parents need to carefully read labels in order to ensure non-dairy beverages are vitamin D fortified. And you can’t always rely on the front of the package to tell you. Check the Nutrition Facts box and look for a daily value (DV) for vitamin D of 45 per cent, which indicates 100 IU vitamin D per 250 ml.
Even if your child does drink milk and/or fortified non-dairy beverages, there’s a good chance he or she is not drinking enough of it to meet daily vitamin D requirements. Kids would need to drink six cups each day to get the 600 IU of vitamin D children, aged one and older, need each day. Children who are obese may require two to four times more to achieve an adequate vitamin D level.
Very few foods have vitamin D naturally. Salmon (447 IU per 3 ounces) and tuna (154 IU per 3 ounces) are among the best sources. Eggs (41 IU per yolk) and cheese (14 IU per 2 ounces cheddar) provide a little. Besides fortified milk and non-dairy beverages, some brands of orange juice, yogurt and breakfast cereals may also have added vitamin D.
For Canadian children who don’t get enough vitamin D from their diet, a vitamin D supplement is recommended in the fall and winter and for some, year-round. Children’s multivitamins contain 400 IU; vitamin D is also available in capsules, tablets and drops for children.
Taking more vitamin D than required is not better. Safe upper daily limits are 2500 IU (aged 1-3), 3000 (aged 4-8) and 4000 IU (aged 9 and older). Excess vitamin D can cause nausea, vomiting, poor appetite, weakness, heart rhythm problems and kidney damage.
Note: For children aged two and younger, soy, rice, almond, coconut and other plant-based beverages – fortified or not – are not suitable alternatives to breast milk or whole cow’s milk as they are generally lower in protein, fat and calories.
Source: CMAJ, October 20, 2014.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.