Vitamin D and Pregnancy

What is Vitamin D? 
While we often call it a vitamin, Vitamin D actually functions as a hormone within the body. It is essential for bone and tooth health, immune function, brain health, and the regulation of inflammation.

Why is Vitamin D important during pregnancy?
This nutrient is involved in numerous processes that ensure a healthy pregnancy, from aiding implantation to promoting the maturation of fetal lungs.
Benefits for Mom:
Maintaining adequate levels is linked to a lower risk of several complications, including:

• Preeclampsia 
• Gestational Diabetes 
• Bacterial Vaginosis 
• Intrahepatic Cholestasis of Pregnancy (ICP): While not a known cause, there is a correlation between low levels of Vitamin D and this rare liver issue.

Benefits for Baby:

• Skeletal Development: Vitamin D helps the body absorb calcium and phosphorus, which are critical for building healthy bones.
• Reduced Risk of Preterm Birth: One study showed that mothers with adequate levels had a 60% lower risk of preterm birth.
• Long-term Health: Proper levels can protect your child from cavities, lower bone density, and potentially autoimmune diseases later in life.

Why is deficiency so common?
Deficiency is an epidemic, affecting up to 95% of pregnant women in some areas. Several factors influence this risk:

• Latitude: If you live north of the 37th parallel (Kansas is just above the 37th parallel), your skin cannot synthesize enough Vitamin D from the sun during winter and spring.
• Skin Color: Melanin acts as a natural sunscreen. Those with darker skin tones may require up to six times more sun exposure to produce the same amount of Vitamin D as those with lighter skin.
• Modern Lifestyle: Spending time indoors and using sunscreen (SPF 30 blocks 95–98% of Vitamin D production) prevents the skin from synthesizing Vitamin D when exposed to sunlight.
• Body Weight: High levels of body fat can sequester Vitamin D, making it less available for the body to use.

How will I know if I am Vitamin D deficient?
As part of your prenatal care, your midwife will order a test called Vitamin-D 25 hydroxy to check your level at the start of care, and again around 30 weeks gestation. 

What can I do to ensure I’m getting enough Vitamin D?
While food is a great starting point, it is difficult to get enough Vitamin D from diet alone.

• Research shows  that 4,000 IU of Vitamin D3 daily is safe and effective for reaching functional levels in both mother and baby.
• Look for Vitamin D3 (cholecalciferol) rather than D2, as it is more effective at sustaining blood levels.
• Vitamin D works best when taken with fatty foods and paired with nutrients like Magnesium, Vitamin K2, and Vitamin A 28.
• If feasible, aim for mid-day sun (10:00 AM to 2:00 PM) without sunscreen for a short period (20 minutes or so), taking care not to burn.
• Include fatty fish (salmon, mackerel, tuna), egg yolks, beef liver, and fortified milks in your diet.

Sources:
https://pmc.ncbi.nlm.nih.gov/articles/PMC7905986/
https://www.medicalnewstoday.com/articles/161618
https://nutritionsource.hsph.harvard.edu/vitamin-d/
https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/vitamin-d-deficiency/faq-20058397
https://lilynicholsrdn.com/vitamin-d-pregnancy/