Vitamin D For Kids' Bones….and More!
By Lori S. Brizee MS, RD, LD
Vitamin D is often called the “sunshine vitamin”. Our main source is our skin’s exposure to ultraviolet B rays from sunlight. However, for those of us living at high latitudes (above the 42nd parallel; about the Oregon/California border) the sun is at an angle which prevents us from getting much, if any, ultraviolet B rays between November and February, and less than people at lower latitudes between March and October. When we wear sunscreen to prevent skin cancer we block ultraviolet B rays, so we do not get vitamin D from the sun.
Why is this important?
Vitamin D makes it possible for us to absorb calcium from foods. Without adequate calcium and vitamin D, children and adolescents’ bones cannot develop, resulting in rickets, and adults risk losing bone and developing osteomalacia (soft bones) and/or osteoporosis (thin brittle bones). Over the past 5 to 10 years, researchers have discovered that vitamin D has many functions in addition to bone health. Vitamin D helps prevent auto-immune disorders such as type 1 and type 2 diabetes and multiple sclerosis and many cancers, including colon, prostrate and breast. All of these conditions occur more often in people living at higher latitudes and thus getting less natural vitamin D from the sun. Vitamin D is thought to have a role in alleviating depression, increasing muscle strength and regulating body weight as well.
Our main food sources of vitamin D are seafood and fluid milk--vitamin D occurs naturally in seafood and milk is fortified with 100 IU vitamin D per cup (see table 2). We can meet our needs via sunlight with about 30 minutes of midday sun exposure to the arms and legs twice each week (no sunscreen); year round if we live at lower latitudes and in the summer at higher latitudes. Right now, a very reasonable and safe goal is 400 IU/day for children up to about five years of age (45 lbs) and anywhere from 800 to 2000 IU vitamin D for older children, adolescents and adults, with a combination of vitamin D-rich foods and a supplement, if midday sunlight exposure is not possible.
How much vitamin D do we need?
The current recommendations for adequate intake of vitamin D (see table 1) are considered low by many researchers and healthcare professionals. In 2008 the American Academy of Pediatrics doubled its recommendations for vitamin D in infants and children from 200 IU/day to 400 IU/day. Some research suggests that children and adults would benefit from even higher doses. A study in Canada showed that children who received less than 8.2 IU vitamin D per pound of body weight had low levels of vitamin D in their blood. A 30-year study in Finland showed that children who were given 2000 IU vitamin D/day starting at birth had an 80% lower incidence of type 1 diabetes than those who did not receive the supplement. Studies in middle-aged adults have shown that vitamin D supplements of 700 to 800 IU/day with about 600 mg calcium resulted in decreased fractures related to osteoporosis. Within the next few years we will probably see more increases in vitamin D recommendations for children and adults, especially those living at northern latitudes.
Current United States vitamin D recommendations (Otten, Hellwig and Meyers (editors); Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. National Academies Press, Washington DC, 2006 pp224-231)
Age Adequate Intake (AI) 2008 American Academy of Pediatrics Recommendation Tolerable upper limit:
- 0-12 months 200 IU (breastfed infants need a supplement within first two months of life)) r 400 IU (Breastfed babies should receive a supplement starting in first few days of life) 1000 IU
- 1 year through 50 years and pregnant/lactating women 200 IU 400 IU for children (no new official recommendations for adults yet) 2000IU
- 51-70 years 400 IU 2000IU
- >70 years 600 IU 2000IU
Vitamin D Content of Selected Foods (Pennington and Douglass, Bowes and Church’s Food Values of Portions Commonly Used, 18th Ed, Lippincott Wiliams & Wilkins, 2005, pp384-388):
- Food Amount Vitamin D (IU)
- Codliver oil 1 tablespoon 1360
- Salmon, Chum canned with bone 3 ounces 190
- Salmon, Pink, canned with bone 3 ounces 530
- Sardines, Pacific, canned in tomato sauce, 1 sardine, 1.3 ounces 182
- Tuna, light, canned in oil, drained 3 ounces 200
- Oysters, eastern, wild, raw 6 medium (84 gm) 269
- Milk, Nonfat, 1%, 2% or whole (fortified with vitamins A and D) 8 fluid ounces 100
- Fortified dry breakfast cereals 1 ounce serving (see package label) ~40
- Shitake Mushrooms 4 mushrooms (15 gm) 249
- White mushrooms ½ cup pieces (70 gm) 53
- Soy nuts 1 oz (28 gm) 100
- Egg 1 large 26 (more if chickens fed vitamin D)
- Human Breast milk 8 fluid ounces 10
So, guide your kids drink their milk, serve the foods listed above, and enjoy outside activities to soak up the sun while having fun!