In last week’s column, I discussed whether multivitamins are appropriate for babies and kids and came out against supplementing mutivitamins as an “insurance policy” for healthy infants, toddlers and preschoolers whose diets are not restricted. But despite my cautious approach to multis in young kids – and my overall “food first” philosophy – I believe that there are certain single-nutrient supplements that may be of benefit in significant segments of the younger population. Among these, vitamin D, iron and omega-3 fats like DHA deserve particular consideration.
Vitamin D: Vitamin D is an essential nutrient for growing children; it enables calcium absorption so that bones can grow and mineralize properly. Higher blood levels of vitamin D have also been associated with a protective effect against a variety of metabolic and autoimmune diseases. Despite its name, however, vitamin D is really a hormone, not a dietary vitamin; it is sparse in the natural food supply, though milk and some dairy products are now fortified with it. Still, it would require six cups of vitamin D fortified milk per day to meet the recommended intake of 600 IU for children through diet alone.
Historically, humans met their vitamin D needs by manufacturing it in their skin from sun exposure, and storing summertime surpluses for use during the winter. However, our ability to produce vitamin D from the sunlight is affected by latitude, season, skin pigmentation, sunscreen use and time spent outdoors. For these reasons, it’s hardly surprising that the majority of Americans have insufficient vitamin D levels.
The current recommended intake of vitamin D is 400 IU per day for infants and 600 IU per day for children ages 1 and up. Data, however, suggest that the vast majority of infants do not meet the recommended intake, and that millions of children ages 1 to 11 may have insufficient blood levels of vitamin D. Children at elevated risk for vitamin D insufficiency include those with dark skin (particularly black and Hispanic children), breastfed infants, and those who are obese or live in the northern hemisphere.
Given the centrality of vitamin D to growth, development and disease prevention; the widespread prevalence of insufficient intake and blood levels; and the low risks of toxicity associated with vitamin D supplementation, a strong case can be made for routine Vitamin D supplementation among many – if not most – groups of children. The American Academy of Pediatrics specifically recommends that all breastfed infants be supplemented with liquid vitamin D soon after birth. On a personal note, vitamin D is one supplement I take myself and have given to my own children since they were just a few weeks old.
Iron: Iron is a component of red blood cells, aiding in the transport of oxygen for normal development of brain and motor functions. Iron deficiency is relatively common among U.S. children – with kids ages six months to 3 years at particular risk due to their high requirements and erratic eating patterns. When iron deficiency is severe, it causes Iron Deficiency Anemia – a reduced red blood cell count that may have consequences for cognitive development.
National data suggest that iron deficiency and IDA combined affect about 11 percent of U.S. toddlers, with prevalence slightly lower among blacks and higher among Mexican-Americans. While these are indeed significant levels, consider the flip side: 89 percent of American toddlers apparently do not have low iron levels. This fact – coupled with the reality that supplemental can cause stomachaches or constipation and puts children at elevated risk for dangerous iron overload when dosed improperly – suggests to me that iron supplements should not be given as an “insurance policy” to healthy young children whose iron levels have not been clinically measured.
Rather, children at high risk for iron deficiency should be screened throughout toddlerhood and beyond to identify iron deficiencies so they can be treated on an as-needed basis. Particularly high risk groups include lower income children, kids born prematurely, vegetarian/vegan children and poor eaters whose regular diets do not contain iron-fortified cereals (oatmeal and Cheerios, for example), red meat, beans/lentils, prunes, egg yolks, or liver. (Spinach is a good source of iron, too, but absorbability is very poor.)
Pediatricians routinely check iron levels at the 9- or 12-month checkup, but if you’re concerned about your child’s iron status, ask your child’s doctor to monitor hemoglobin levels at your annual well-child visits. The test is a simple finger prick, and results are available immediately. By taking this approach, I recently learned that my son is anemic – while his twin sister is not. This enabled me to supplement my son who needed it, and rest assured that I wasn’t unnecessarily supplementing my daughter who didn’t.
[Read: Women: Here's How to Boost Your Iron.]
Omega-3s: “Omega-3s” refer to fatty acids that play a critical role in cell structure and communication, with particular importance for brain function and cardiovascular health. Humans cannot manufacture omega-3s, so it’s essential that we obtain them from our diets. Examples of omega-3s include Eicosapentaenoic acid and Docosahexaenoic acid, which are found in fatty fish such as salmon, sardines, anchovies, halibut, herring and mackerel. Breastmilk also contains omega-3s to meet the needs of infants, and in the past several years, manufacturers have added omega-3s to infant formulas as well. Several plant-based foods, such as flaxseeds and walnuts, contain alpha-linolenic acid, an omega-3 that our bodies are able to convert – albeit inefficiently – into the more biologically-active forms of EPA and DHA.
While minimum recommended intakes required to prevent overt deficiency have been established by the Institute of Medicine, research has not yet resulted in consensus around what an optimal intake is for humans in general and developing children in particular. The World Health Organization currently recommends daily average intakes of EPA/DHA as follows: 100 to 150 mg for kids ages 2 to 4; 150 to 200 mg for kids 4 to 6 years old; 200 to 250 mg for kids ages 6 to 10 and 250 mg daily for kids 10 and older. Since omega-3s are fats and can be stored, children need not consume these levels each and every day, but rather should aim for these average daily intakes over the course of a week.
The good news is that it requires relatively small portions of kid-friendly fish, such as salmon or certain brands of canned white tuna, to meet these needs. A teeny 1-ounce serving of farm-raised salmon – about the size of a business card – contains about 600 mg of combined EPA and DHA – about three days worth for a child ages 4 to 10. (Larger portions, naturally, cover kids for even longer.) Moreover, salmon is a low-mercury fish and can be introduced as early as about 6 months of age. Canned albacore tuna – another kid staple – can also be an excellent source of omega-3s depending on which brand you use, as processing and packaging methods affect content dramatically. Some premium brands of white albacore tuna that are not packed in water can contain between 1,200 to 1,300 mg (!) in a sandwich-sized 2-ounce portion; such brands, like Wild Planet and Vital Choice, also use cans that are not lined with the chemical BPA and have substantially lower levels of mercury than conventional brands due to the smaller-sized fish they use, making them a doubly great choice for developing kids. In other words, small servings of omega-3 rich fish twice weekly should easily meet most children’s needs for omega-3s.
The bad news is that many – if not most – children don’t even eat this much. In such cases, then, it may be appropriate to consider an omega-3 supplement. For infants and children in particular, DHA appears to be the safest form of omega-3 to supplement. As my fellow dietitian Elizabeth Somer, author of “The Essential Guide to Vitamins and Minerals” further explains, “DHA is a major structural fat in the brain, accounting for 97 percent of the omega-3 fats. It plays a role in how cells communicate and is critical for vision during the developing years.” In healthy older school-aged children, supplemental DHA has been investigated in terms of its effect on learning, school performance and/or attention with ADHD. The quality of available data is variable and generally consists of small studies, varying doses and different outcomes being measured. Despite mixed conclusions, the most consistent findings suggest a potential benefit of DHA supplementation on school performance and behavior. If you’re considering an omega-3 supplement for your child, ask your pediatrician what dose s/he suggests and be sure to select a reputable brand.
Tracey Kurland, a dietetic intern and master's degree candidate at Columbia University Teacher's College in New York City, contributed to this article.