In the fall of 2014, the American Academy of Pediatrics released a clinical report on Optimizing Bone Health in Children and Adolescents. Cam Lanier, dietitian, and Dr. Kate Ness, endocrinologist, comment on the clinical report and address questions from Dr. Wendy Sue Swanson, a pediatrician at The Everett Clinic in Mill Creek, a member of Seattle Children’s medical staff and author of the Seattle Mama Doc blog.
Q. Most pediatricians don’t recommend a daily multivitamin for healthy children. However, over the last decade there has been an increased focus on the value of supplemental vitamin D for infants and children. Can you explain the data supporting the need for supplemental vitamin D?
High-quality evidence supports the role of vitamin D in the growth and development of bones. Vitamin D helps to prevent rickets and to build optimal bone mass during infancy, childhood and adolescence in order to prevent fractures in childhood and osteoporosis later in life.1,2
Supplementation is recommended because research has shown that it is very difficult to obtain adequate vitamin D by sunshine alone at latitudes above and below approximately 33 degrees, particularly during the winter months.3 Seattle, located at 47 degrees north, is not in an area with sufficient sunshine to provide adequate vitamin D, especially in the winter.
Also, there are few natural food sources of vitamin D (fatty fish, egg yolk, liver, mushrooms) and few fortified sources (milk, alternative milks, some juices and some cereals). Children have to drink a liter of cow’s milk or formula each day to get 400 international units (IUs) of vitamin D. Consequently, supplements may provide an easy way to ensure adequate vitamin D intake.
Q. What are the benefits of vitamin D beyond building bone mass?
There is limited but growing evidence about other benefits of vitamin D, including decreased risk of:
- Infectious diseases (due to improved immunity)2
- More than a dozen cancers, including colon, prostate, breast and pancreatic cancers2
- Autoimmune diseases, including type 1 diabetes, rheumatoid arthritis, Crohn’s disease and multiple sclerosis2
- Cardiovascular disease2
These benefits are probably related to vitamin D acting as a hormone once it has been hydrolyzed to its biologically active form in the body and to the vitamin D receptors present in most tissues and cells in the body.
Q. What do you typically recommend with respect to supplemental vitamin D? Are there any healthy children who should not have supplements?
It’s safe to recommend 400 to 600 IUs of vitamin D for all healthy children. Because breast milk is a poor source of vitamin D, breast-fed and partially breast-fed infants require 400 IUs of supplemental vitamin D daily. Most kids’ vitamins have either 200 or 400, so parents should read the label. It’s rare that children’s bodies overproduce vitamin D or can’t break it down.
Subpopulations of children may have higher requirements for vitamin D at baseline due to conditions associated with reduced bone mass and increased fractures or conditions that affect the efficiency of vitamin D absorption and utilization. These subpopulations, which should undergo periodic screening and have a target vitamin D level of 30 ng/mL,5 include children with:
- Chronic diseases such as cystic fibrosis, connective tissue disorders, cerebral palsy, inflammatory bowel disease and muscle diseases that limit weight-bearing
- Genetic conditions such as osteogenesis imperfecta and Turner syndrome
- Endocrine conditions such as growth hormone deficiency and diabetes mellitus
- Eating disorders
- Conditions that require long-term use of medications such as anticonvulsants, glucocorticoids, chemotherapy, antifungals or retrovirals
Q. Is milk necessary in a child’s diet?
Cow’s milk is not necessary for a child’s diet, but children do need the nutrients in cow’s milk. Each glass of cow’s milk provides 300 mg of calcium and 100 IUs of vitamin D, as well as protein and other nutrients.
If a child can’t drink cow’s milk, they can obtain equivalent amounts of calcium and vitamin D from fortified milk alternatives such as soy milk, almond milk, hemp milk and coconut milk, or fortified orange and apple juice.
However, calcium may not be as easily absorbed from some of these milk alternatives,6 and juice is high in sugar and low in the fiber and other nutrients that whole fruits provide. Calcium is widely available in other dairy products such as cheese and yogurt, as well as in some nondairy products such as calcium-fortified tofu, green leafy vegetables, legumes and even rhubarb.5 Dietary intake of calcium is recommended over supplements to encourage healthy dietary habits.
We know that children’s rate of bone mass gain is greatest at times when they are growing the fastest, so calcium is very important in adolescence, when calcium intake tends to decline.
- Institute of Medicine, Dietary Reference Intakes for Vitamin D and Calcium. Washington, DC: National Academies Press;2011.
- Holick MF, Brinkley NC, Bischoff-Ferrari HA et al, Endocrine Society. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96(7):1911-1930.
- Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357:266-281.
- Gupta A, Sjoukes A, Richards D et al. Relationship between serum vitamin D, disease severity, and airway remodeling in children with asthma. Am J Respir Crit Care Med. 2011;184(12):1342-1349.
- Golden NH, Abrams SA, Committee on Nutrition. Optimizing bone health in children and adolescents. Pediatrics. 2014;134:e1229-e1243.
- Heaney RP, Dowell MS, Rafferty K, Bierman J. Bioavailability of the calcium in fortified soy imitation milk. Am J Clin Nutr. 2000 May;7(5):1166-1169.