The right recommendation for Vitamin D
We know that Vitamin D is important in preventing rickets in the young and osteoporosis (a weakening of the bones) with advancing age. But we are now learning that Vitamin D seems to have an important role in immune function, high blood pressure and preventing diabetes. The problem is that it doesn't necessarily mean the dose needed to heal bones is the same dose that's needed for these other roles.
We've also learned that Vitamin D deficiency is far too common. That may be understandable since only fair-skinned individuals in sunny areas wearing no sunscreen benefit from the sun's rays that can create vitamin D in the skin. Plus, it's hard to get it in our diets, since the only source is fish, and milk products where Vitamin D has been added.
Dosing Recommendations.
With all of this, the Institute of Medicine in 2010 revised its recommendations to increase how much vitamin D we should take in. They wanted to be sure we get enough but not too much, since kidney stones and other possible problems can come from too high a dose. They recommended 400 International Units (IU) daily for infants and 600 IU for everyone else to age 70, including breastfeeding mothers.
There are two concerns: these levels are hard to achieve with just diet alone (it would take two to six dairy servings a day to reach the 600 IU recommended at the current levels of supplementation). And a bigger concern: these levels may still be too low.
Why? In Japan, 1,200 IU of vitamin D per day during the winter reduced the risk of having the flu by 42 %. Babies receiving 2,000 IU per day were 88 % less likely to develop diabetes over the next 30 years, and black teens on that same dose reduced their potential for high blood pressure and atherosclerosis (the basis for heart attacks), while 400 IU did not produce the same effect.
Additionally, a US study showed that pregnant women who took 4,000 IU in their second and third trimesters had a reduced risk of pregnancy-related diabetes, infections, high blood pressure, and premature births, with no ill effects, compared to women who took 400 IU of vitamin D every day. And the babies had higher vitamin D levels as well.
The Endocrine Society's Clinical Practice Guidelines
As a result, I am now more in line with the Endocrine Society's Clinical Practice Guidelines, which recommend at least 400 to 1,000 IU for infants; in fact, 1,200 seems reasonable based on the Japanese data. I also support the Endocrine Society's recommendations of 600 to 1000 IU for older children, 1,500 to 2,000 IU for adults and pregnant or lactating women, preferring the higher range of values, with the note that maternal supplementation of 2,000 IU while lactating achieves vitamin D levels for infants comparable to infants receiving 400 IU daily.*
I would use the lower amounts cited in the range if anyone in the family has had kidney stones or kidney disease (or at least discuss the options with your doctor), since excess calcium can promote stones and damage. To prevent problems, your doctors should check your blood levels to ensure calcium and vitamin D levels are healthy, since these higher doses do involve some risk.
Do know that these suggestions are higher than the American Academy of Pediatrics report from 10 years ago. They still stand by their recommendation 1that a supplement of 400 IU of vitamin D a day be given to a child who is not receiving that in the diet, and the Institute of Medicine recommends 600 IU for everyone from 1 to 70 years of age, including pregnant and lactating women.
The Risks
Ten (10) times the current levels of vitamin D were added to milk in Britain in the 1950s. A lot of children had problems. They lost their appetites, grew weak and started vomiting as calcium was deposited in their tissues. Some developed high blood pressure, kidney stones, and kidney failure. But these are much, much higher amounts that the Endocrine Society is recommending.
However, if you or your child develops nausea and vomiting, loss of appetite, excessive thirst, frequent urination, constipation, abdominal pain, muscle weakness, muscle and joint aches, confusion, or fatigue, stop supplementing at that level and see your doctor to have blood levels and lab tests done to avoid problems.
And do remember that the total amount needed includes what you or your child gets in the diet. So any supplement should consider your child's intake. If you have questions about how much to give, check with your own physician before giving your child vitamin D (or other) supplements.
Bottom Line
Vitamin D deficiency is common. The Endocrine Society has increased their dose recommendations while older recommendations suggest less. Fortunately, Vitamin D blood levels can guide treatment. But this is an active field of research because Vitamin D seems to have many uses beyond bone health. So expect to see other updated changes over the next several years.
