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    Jennifer Nelson, M.S., R.D. and Katherine Zeratsky, R.D.

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  • Jan. 17, 2009

    Vitamin D: Benefits in pregnancy and beyond

    By Jennifer Nelson, M.S., R.D. and Katherine Zeratsky, R.D.

10 comments posted

Vitamin D is a hot topic, so let's keep the discussion going...

Your prenatal level of vitamin D may play a role in determining your health later in life. Sound far fetched? It may not be.

During pregnancy, the active form of vitamin D increases significantly, particularly in the second and third trimesters. During this time, the baby's bones are developing, as are the brain, the nervous system, and the other organs.

Recently, a review published in the journal "Nutrition Reviews" looked at the research about vitamin D and maternal, fetal, and infant health. Although much more research is required, it appears that vitamin D contributes to improving pregnancy outcomes, such as decreasing the risk of pre-eclampsia, and improving length of gestation, birth weight, and infant bone mineralization. It also appears that sufficient vitamin D in early life may decrease the risk of health problems later in life such as schizophrenia, brain tumors, asthma, multiple sclerosis, and autoimmune diseases such as type 1 diabetes.

These findings don't mean you should run to the local pharmacy for a mega dose of vitamin D. In fact, the article also warns of potential adverse effects of too much vitamin D on the cardiovascular system and allergies. Much is still to be learned and hopefully gained from further research. But here's what I can share as safe advice now:

If you are pregnant:

  • Take a prenatal vitamin. If you can't tolerate that, take a regular multivitamin. Look for one with at least 200 international units of vitamin D (the U.S. recommended daily allowance).
  • The current tolerable upper limit is 2000 IU. The Canadian Pediatric Society actually suggests that this level may be appropriate for winter pregnancies.

If you have infants/children:

  • Infants fed breast milk need a vitamin D supplement, 400 international units daily, according to a 2008 report of the American Academy of Pediatrics (AAP).
  • Infants fed formula need a vitamin D supplement until they are drinking at least a liter of formula daily. Again, the AAP recommends up to 400 international units to complement the amount in formula. Consult with your child's doctor or dietitian.
  • Older children drinking less than a quart of vitamin D-fortified milk daily need a vitamin D supplement, up to 400 international units daily.
  • Infants and children are at greater risk of toxicity — so be cautious with your dosing and administration.

To you and your children's health,

Katherine

10 comments posted

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  • October 20, 2009 2:13 p.m.

    Current recommendations on Vitamin D intake are based on rickets prevention and are clearly inadequate to maintain adequate 25(OH)D levels. A pale-skinned person in Florida will get 10,000 IU's/day from half-body exposure to 15 minutes of sun (without sunscreen). For those confused about the 1,25(OH)2-D and 25(OH)-D tests, the 1,25 test is testing for "activated" vitamin D, a process where your kidneys convert 25(OH)-D through a closely regulated process into 1,25(OH)2-D. The 1,25(OH)2-D test is verifying that internal conversion process and pregnant women after the 12th week should be at the top of the normal bar or slightly over. If the value is way outside the bounds, they should be tested for sarcoidosis or other risk factors for Vitamin D sensitivity. 25(OH)-D is the simple measure of D3 in your blood serum and is the correct test to measure deficient/adequate/excessive levels of Vitamin D. Recent studies are substantiating effective and low risk daily doses of up to 10,000 IU's/day D3 and that pregnant women who get at least 4000 IU's/day have a lower risk of several risk factors including pre-eclampsia, gestational diabetes, premature birth and low birth weight. Further, breastfeeding mothers taking at least 6400 IU's/day passed on more than 400 IU's/day D3 in their breastmilk, solving the mystery of how babies avoided rickets before supplements (their mom's got enough sun). Up to 10k/day is safe and extremely helpful, but use the 25(OH)D test to moni

    - Ross

  • October 5, 2009 1:59 p.m.

    To be accurate, the Canadian Pediatric Society does not just say to supplement ONLY for winter pregnancies, but ESPECIALLY for winter pregnancies. "Consideration should be given to administering 2000 IU of vitamin D daily to pregnant and lactating women, especially during the winter months, to maintain vitamin D sufficiency. The effectiveness of this regimen and possible side effects should be checked with periodic assays for 25(OH)D and calcium (recommendation grade A)." And: "The tolerable upper intake level in adults has been arbitrarily set at 2000 IU/day. However, a recent risk assessment based on a review of relevant, well-designed clinical trials of vitamin D in healthy adults by Hathcock et al (56) showed an absence of toxicity in trials that used vitamin D dosages greater than or equal to 250 µg/day (10,000 IU/day vitamin D3) and supported the selection of this value as the upper limit for healthy adults (evidence level II-2)."

    - JM

  • August 27, 2009 11:04 a.m.

    Rick- The standard recommendations for pregnancy do not include additional vitamin D beyond that provided in prenatal vitamins. Toxicity is possible with fat soluble vitamins and so she should discuss this situation with her provider promptly.

    - MayoClinic.com Staff

  • August 19, 2009 3:05 p.m.

    My wife is in the beginning of her eighth month and was taking 400 iu of D2 in her prenatal and 1,000 iu D3 additionally. Here levels were tested and her 1,25 levels came back at about twice top of range. Her 25 OH levels were midrange. The nurse practitioner told her to discontinue the additional 1,000 iu as her 1,25 was so high. I told her I thought it was normal - and irrespective of supplementation - for 1,25 to be high and that 25OH was the marker of importance. She said I was wrong and that sine D is fat soluble, it can be toxic. What to do?

    - Rick

  • July 1, 2009 4:54 p.m.

    It is unconscionable that testing for vitamin D level was not mentioned in this piece. To put 200IU as a minimum is also misinformation. That dose is way too low. However, to attain the correct dose, a 25(OH)D level is crucial.

    - Bonnie C. Minsky MA, MPH, CNS, LDN

  • June 18, 2009 5:17 a.m.

    It is ridiculous to suggest that a breastfed infant needs any supplements whatsoever, assuming that the person providing the breast milk is getting all the nutrients needed to supply herself and the infant. The US is currently in the midst of a fair amount of vitamin D mania...anyone who watches health trends has seen this happen with other things, so please, let's be rational about this. Additionally, almost all milk is vitamin D fortified, and there's this big shiny thing in the sky that's supposed to give us vitamin D as well. Enough with the supplements already!

    - Evan

  • March 9, 2009 8:03 p.m.

    I found this article to be frustratingly vauge -- there is a HUGE jump between: "Take somewhere between 200 and 2,000 IU per day" -- that is one heck of a range. What is the ideal? What do researchers say? Is there an ideal form of Vitamin D, which seems to come from different sources? What is this vitamin D test that the other posters mention? I also am disappointed with this- - when I saw the Google result saying that this article was from the Mayo Clinic, I clicked on it thinking it would be the best article. But this is way too vague: "In fact, the article also warns of potential adverse effects of too much vitamin D on the cardiovascular system and allergies. Much is still to be learned and hopefully gained from further research. " Umm...OK, WHAT were those guidelines? What did THEY define as "too much" in their study? I'm not asking the posters to speculate on untested data, but they could at least provide more information from this study. Anyone else - please post your useful (research-supported) Vitamin D + pregnancy links here! Thanks!

    - Guest

  • February 13, 2009 1:22 a.m.

    There are more and more test coming out about the great importance of Vit D and how many of us lack it! Not only should pregnant women be tested so should everyone! I have read some studies which recommend 400 IU, yet this does not mean we should stop there. I have read studies suggesting 2000 iu. I found this article frustrating b/c it left out the importance of the test!

    - Lindsay

  • January 26, 2009 1:53 a.m.

    Misinformation equals bad information. And bad information is harmful, not what 'do no harm' professionals should be handing out. My daughter had high blood pressure in the last few weeks of her pregnancy. Then she had a cesarean, then two weeks later she had a stroke. We are so happy she lived! Her mother-in-law cared for our darling granddaughter for nine months. But my daughter couldn't nurse her baby. Her medical plan paid out $200,000 (imagine if the plan had been inadequate!). She didn't lose her job but it has been difficult since she went back full time. All for the lack of $20 worth of vitamin D, and D test! What a waste! A year and a half later she still can't use her left hand and she walks with a gimp. She did take a pre-natal vitamin, it had the so-called recommended daily allowance of D, that harmfully incorrect 200 IU. I blame the medical profession for not knowing enough about nutrition. If a person can make 20,000 IU of D in 20 minutes of full-body summer exposure, then clearly 200 IU a day is not going to do it. My daughter followed medical advice: she used sunscreen, and avoided fish to avoid mercury and dioxin. When her doctor ordered a 25-OH-D blood test in the hospital after the stroke, she was indeed very low in D. Doctors are not psychic so they cannot guess what a person's D supplementation should be. There are way too many variables to be able to have a one-size-fits-all RDA. Please, EVERY pregnant woman needs a 25-OH-D test!

    - Lauren Ayers

  • January 17, 2009 10:08 a.m.

    The article (1) fails to emphasize the need to test in order to determine the necessary daily dose, (2) refers to old and generally inadequate daily dosage recommendations, (3)does the usual CYA regarding toxicity, (4) fails to inform that cholecalciferol is the preferred form. A publication from Mayo should do better. See "Urgent need to recommend an intake of vitamin D that is effective', AM.J.Clin. Nut. 2007, 85:649-50.

    - Auburn

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