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/

There is so much information out there about pregnancy, birth and postpartum  Between Google, books, social media, the news, friends, family, and sometimes total strangers who feel they need to give you advice, it can be challenging to know what is trustworthy or evidence based and what is not. 

I have some criteria I use to determine if information is trustworthy that I thought I would share.

• Is there money involved? I've found information being pushed by entities that are using that information to make money. I understand trying to sell a product, but I have issues with manipulating information to support a particular ideology whether it's related to immunizations, or getting your baby to sleep through the night.
• Are sources for the information shared or  are statements made relating to research or evidence without citing the sources? I am skeptical of any research or evidence based claims being made when the sources used for those claims aren't shared.
• One size fits all solutions or this is the only way to do it statements do not make me comfortable. We are all unique and what may work for one person may not work for someone else.
• If the information is based on a study, is there more than one study that got the same or very similar results? Having more than one study showing the same or very similar results indicates the results are reliable.

My favorite websites for pregnancy and birth related information are:

• Evidence Based Birth
• Dr. Sarah Wickham
• The National Institutes of Health
• Cochrane Review
• World Health Organization
• Stanford Health
• The Mayo Clinic
• The Society for Maternal-Fetal Medicine
• Pub Med

As we try to sort through all the information that is available at the touch of our fingertips online, I hope you find my criteria helpful for finding trustworthy, evidence based information. I would love to hear what  criteria you use. You can share your criteria in the comments.