While we know that Vitamin D levels which simply prevent rickets are not adequate to provide optimal health, we are continuing to explore exactly how much vitamin D supplementation is beneficial. There is controversy among scientists over this issue. Some researchers and professional groups now recommend 75 nmol/L and perhaps higher. (Am J Clin Nutr 2006;84:18 -28)
If the new guidelines are adopted, a new study (Ginde, Adit A et. al. Vitamin D insufficiency in pregnant and nonpregnant women of childbearing age in the United States. AJOG – corrected proof 12 Jan 2010) indicates that current levels of vitamin D in most prenatal vitamins (400 IU) may not be enough for optimal health for many childbearing women.
The study looked at a large group of pregnant women and non-pregnant women of childbearing age. One third of the pregnant women and 42% of the non-pregnant women had blood levels of < 50nmol/L. Vitamin D levels were not consistent over the entire group of women. Vitamin D levels varied in individuals but seemed to cluster around:
Race: Black women were significantly more likely to be deficient in Vitamin D than Caucasian women. Hispanic women were less likely to be deficient than black women but more likely than Caucasian women. Much of our vitamin D comes from sunshine exposure. Darker skin requires more sunlight to absorb the same amount of vitamin D.
Exercise: Women who did not exercise were more likely to be deficient in Vitamin D than women who did exercise. Women who exercised outdoors were least likely to be deficient.
Prenatal Vitamins Women who took prenatal vitamins were less likely to be deficient in Vitamin D than those who didn’t take vitamins.
Breastfeeding women were more likely to be deficient in Vitamin D than non-breastfeeding women.
Age did not make a significant difference; younger women and older women were fairly consistent in their vitamin D levels.
Socio-economic levels did not make a significant difference. Women of different economic means were fairly similar.
Factors not discussed in this study but which may be significant include:
Where you live: Women who live closer to the equator get more direct sun and so often need less Vitamin D supplementation than women who live further from the equator.
Clothing: Women who choose to completely cover their skin will need more Vitamin D supplementation than women who expose more of their skin to the sun.
Your previous habits: The body stores extra Vitamin D so if you have taken supplements for a long time, exercised, been in the sun a lot, or eaten fortified foods, you will have better stores of Vitamin D than a woman who made other choices.
Your diet: While much vitamin D is produced from sunshine exposure, foods do play a role in vitamin D levels. Some fish is naturally high in vitamin D. Much of dietary vitamin D comes from enriched foods such as milk and breakfast cereals.
If vitamin D comes from the sun, how about tanning?
Tanning beds emit UVA rays. This type of ray does not produce Vitamin D. It is also provides a significant increase in risk for melanomas (a dangerous type of skin cancer). Vitamin D is produced by the UVB rays in natural sunshine. However, too much sun can significantly increase your chances of developing skin cancer. Talk to your doctor about what is a reasonable amount of sun for your skin type in your location.
Outdoor exercise is GREAT during pregnancy but do consistently wear a sunscreen with an SPF of 30 or higher, especially on your face, neck, and arms. Sunblocks for babies have a mineral, instead of a chemical block. While regular (chemical) sunblocks are believed to be safe for pregnant women, some women feel more comfortable with the mineral block.
Why is my Vitamin D level important?
Babies are almost entirely dependent on their mothers for vitamin D. Tests on baby’s cord blood and Mom’s blood levels at birth show strong correlations. Breastmilk concentrations of Vitamin D are directly related to a mother’s serum levels of vitamin D.
Vitamin D helps your (and baby’s) body to absorb calcium and is important for the mineralization (hardening) of bones. Insufficient Vitamin D levels are also associated with childhood wheezing, an increased chance of developing type 1 diabetes, multiple sclerosis, and other diseases. We know that adequate vitamin D is necessary for the placenta to develop and function properly.
Adequate Vitamin D is crucial to good health. Consider your need for vitamin D supplementation. Talk to your doctor about your risk factors, whether a blood test is advisable, and what levels might be most appropriate for you and your baby!
Nourish yourself and your child!
Ingredient | IU |
Salmon – 3 ½ ounces | 360 |
Tuna (light, not white, is better) – 3 ounces | 200 |
Sardines canned in oil – 1 ¾ ounces | 250 |
Milk, nonfat or reduced fat, vitamin D fortified – 1 cup | 98 |
Ready to eat cereals fortified with vitamin D – ¾ to 1 cup | 40 |
Egg – 1 whole | 20 |
Liver – 4 ounces raw | 15 |
Cheese – 1 ounce | 12 |
Nourish yourself and your child!
Note: Vitamin D is measured both in micrograms as well as international units (IU). 5 mcg =200 IU
The current US RDA for pregnant women is 200-400 IU (or 5-10 mcg) daily; The Institute of Medicine has recommended 1000 IU (25 mcg)
This section contains articles and guidance for healthy eating whether you are working on becoming pregnant, expecting or have a new baby. Articles cover information including what to eat, controlling nausea, breastfeeding and vitamins.