The Critical Role of Vitamin D for New Moms and Babies

The Critical Role of Vitamin D for New Moms and Babies

Pregnancy and early infancy mark significant periods in a person’s life, demanding utmost care and attention to ensure optimal health and development. Among the essential nutrients needed during these stages, Vitamin D stands out for its pivotal role in maternal and infant well-being. In this comprehensive exploration, we delve into the critical importance of Vitamin D for new moms and babies, discussing its necessity, sources, deficiency testing, treatment methods, and the latest literature supporting its significance.

Mechanism of Vitamin D

Vitamin D, a fat-soluble vitamin, facilitates the absorption of calcium and phosphorus. 

Here’s a breakdown of how Vitamin D is used in the body.

1.Sun Exposure: When your skin is exposed to sunlight, a precursor molecule in your skin called 7-dehydrocholesterol undergoes a chemical reaction, converting it into pre-vitamin D3.

2. Conversion in the Liver: Pre-vitamin D3 then travels to the liver, where it undergoes further modification to become 25-hydroxyvitamin D [25(OH)D], also known as calcidiol. This form of Vitamin D is the major circulating form in the bloodstream and serves as an indicator of overall Vitamin D status.

3. Activation in the Kidneys: 25(OH)D travels to the kidneys, where it undergoes another transformation catalyzed by an enzyme called 1-alpha-hydroxylase, resulting in the production of the active form of Vitamin D, known as 1,25-dihydroxyvitamin D [1,25(OH)2D], or calcitriol.

4. Regulation of Calcium and Phosphorus: Calcitriol plays a crucial role in regulating calcium and phosphorus levels in the body. It enhances the absorption of calcium and phosphorus from the intestines into the bloodstream, ensuring an adequate supply for various physiological processes.

5. Bone Health: One of the primary functions of Vitamin D is to maintain bone health by promoting calcium absorption in the intestines and preventing calcium loss in the urine. Adequate Vitamin D levels help ensure proper mineralization of bones, preventing conditions like rickets in children and osteomalacia in adults.

6. Muscle Function: Vitamin D also contributes to muscle function and strength by maintaining calcium levels within muscle cells. Sufficient Vitamin D levels may help reduce the risk of falls and fractures, particularly in older adults.

7. Immune Regulation: Emerging research suggests that Vitamin D plays a role in modulating the immune system, potentially reducing the risk of autoimmune diseases and supporting immune function.

8. The relationship between Vitamin D and mental health is an area of growing research interest, with evidence suggesting that Vitamin D may play a role in various aspects of mental well-being. Here’s an overview of the relationship between Vitamin D and mental health:

  • Mood Regulation: Vitamin D receptors are present in areas of the brain involved in mood regulation, such as the hippocampus and prefrontal cortex. Studies have suggested that Vitamin D may influence the synthesis and release of neurotransmitters like serotonin, which are involved in mood regulation. Low levels of Vitamin D have been associated with symptoms of depression and anxiety.
  • Cognitive Function: Adequate Vitamin D levels have been linked to better cognitive function and a reduced risk of cognitive decline in older adults. Research suggests that Vitamin D may play a role in neuroprotection, promoting nerve growth and repair, which could contribute to maintaining cognitive health.
  • Seasonal Affective Disorder (SAD): Seasonal Affective Disorder is a type of depression that occurs at a specific time of the year, usually during the winter months when sunlight exposure is reduced. Vitamin D deficiency, resulting from decreased sunlight exposure during winter, has been implicated in the development of SAD. Supplementing with Vitamin D or light therapy, which mimics natural sunlight, has shown some benefit in managing SAD symptoms.
  • Schizophrenia and Psychotic Disorders: Some studies have found an association between Vitamin D deficiency during prenatal or early life stages and an increased risk of developing schizophrenia and other psychotic disorders later in life. However, further research is needed to establish a causal relationship and understand the underlying mechanisms.
  • Neuroinflammation: Vitamin D has anti-inflammatory properties and may help modulate immune responses in the central nervous system. Dysregulation of immune responses and neuroinflammation have been implicated in various mental health disorders, including depression, anxiety, and schizophrenia. Vitamin D’s anti-inflammatory effects may contribute to its potential role in mental health.

While these findings suggest a potential link between Vitamin D and mental health, it’s essential to note that the relationship is complex, and Vitamin D supplementation is not a standalone treatment for mental health disorders. Factors such as genetics, lifestyle, diet, and environmental influences also play significant roles in mental well-being. Therefore, further research is needed to elucidate the mechanisms underlying the relationship between Vitamin D and mental health and to determine the potential therapeutic implications. Individuals concerned about their mental health should consult with healthcare professionals for personalized assessment and treatment recommendations.

Vitamin D Needs Increase During Pregnancy

During pregnancy and breastfeeding, the recommended daily intake of Vitamin D escalates to 400- 600 IU/day, ensuring adequate support for the developing fetus and newborn.  Insufficient levels of Vitamin D during these phases can elevate the risk of complications such as preeclampsia, low birth weight, and preterm birth, underlining the significance of supplementation to avert adverse outcomes. Moreover, a randomized control trial even advocated for pregnant women taking up to 4,000 IU of daily vitamin D to prevent preterm labor/births and infections.  Talk to your OB/GYN for the right amount of Vitamin D for your individualized health and verify the amount of vitamin D in your prenatals.  

Benefits of Vitamin D for Newborns and Infants

Beyond skeletal health, Vitamin D offers a myriad of benefits for newborns and infants. It shields against infections, asthma, and eczema while potentially reducing the likelihood of type 1 diabetes. Moreover, Vitamin D plays a pivotal role in cognitive and neurodevelopment, underscoring its influence on a child’s academic performance, behavior, and overall growth trajectory. Recent studies have further elucidated the importance of Vitamin D in maternal and infant health. For instance, a study published in the Journal of Nutrition found that maternal Vitamin D deficiency during pregnancy was associated with an increased risk of gestational diabetes mellitus and low birth weight (Aghajafari et al., 2013). Another study published in JAMA Pediatrics highlighted the link between maternal Vitamin D status during pregnancy and offspring neurodevelopmental outcomes, emphasizing the long-term implications of adequate Vitamin D levels for child development (Whitehouse et al., 2012).

For infants, the recommendations for Vitamin D supplementation vary depending on the country and healthcare guidelines. However, the end goal is for the breastfeed baby to receive a minimum of 400 IU of vitamin D.  

  • American Academy of Pediatrics (AAP): The AAP recommends that exclusively and partially breastfed infants receive a daily Vitamin D supplement of 400 IU (international units) starting from the first days of life. For breastfeeding mothers, the AAP suggests they continue taking prenatal vitamins containing Vitamin D or supplement with 600 to 800 IU of Vitamin D daily to ensure sufficient levels in breast milk.
  • Health Canada: Health Canada recommends a daily Vitamin D supplement of 400 IU for breastfed infants until they reach one year of age. For breastfeeding mothers, Health Canada advises a daily intake of 600 IU of Vitamin D to ensure adequate levels in breast milk.
  • National Health Service (NHS) UK: The NHS suggests that breastfeeding mothers should take a daily Vitamin D supplement of 10 micrograms (400 IU) to ensure they and their breastfed infants receive sufficient Vitamin D.
  • World Health Organization (WHO): The WHO recommends a daily Vitamin D supplement of 400 IU for infants and children under five years of age who are at risk of Vitamin D deficiency. They also advise lactating mothers to take Vitamin D supplements if they have limited exposure to sunlight or are at risk of deficiency.

In the 4th trimester: How New Moms and Babies Can Obtain Sufficient Vitamin D

Attaining optimal Vitamin D levels during pregnancy and lactation necessitates diverse strategies. Moderate sun exposure, approximately 10-15 minutes per day, enables the skin to synthesize Vitamin D; however, precautions against excessive sun exposure are vital to prevent sunburn and skin damage. Additionally, incorporating Vitamin D-rich foods such as fatty fish, egg yolks, and fortified products into the diet can augment intake. When dietary sources are insufficient, supplements offer a reliable means of meeting the required Vitamin D levels, with dosage tailored to individual needs under healthcare provider guidance. Furthermore, breastfeeding mothers should prioritize maintaining their own Vitamin D levels to ensure adequate transfer of the nutrient to their infants via breast milk.

Breastfed babies can receive this supplementation directly. An alternative way is for breastfeeding mothers to increase her own intake of vitamin D supplementation safely to 6400-8000 IU/day.  Formula fed babies receive adequate amounts in their formulas.  When newborn feeding is from breastmilk and formula or families are transitioning from breastfeeding to formula feeding, supplementation of vitamin D should continue until the baby is receiving over 50% of nutrition from formula. 

Deficiency, Testing and Treating

Research has shown that 40-60% of the US population is vitamin D deficient.  Contributing factors include lack of foods that contain vitamin D, lactose intolerance, and usage of sunscreen. Other factors can include the ability to make/absorb vitamin D.  In terms of sunscreen which prevents skin care, most sunscreen products are activated after 15 minutes of application.  Thus, applying sunscreen right before exposure can ensure the 10-15 minute exposure needed while balancing the protection from sun exposure.  

Regular assessment of Vitamin D status through blood tests is suggested during pregnancy to detect deficiencies.. Upon diagnosis, healthcare providers prescribe high-dose supplements to rectify deficiencies, followed by maintenance therapy to sustain optimal Vitamin D levels. A combined approach involving supplementation and judicious sun exposure proves effective in addressing deficiencies and safeguarding maternal and infant health.

Take Home Message

In essence, Vitamin D emerges as a cornerstone of maternal and infant health, exerting profound impacts on bone strength, immune function, and neurodevelopment. By prioritizing adequate intake of Vitamin D through sunlight exposure, dietary sources, and supplementation, expectant mothers can optimize outcomes for themselves and their babies. Regular screening for deficiency and prompt intervention further enhance the prospects of a healthy pregnancy and infancy. With ongoing research continuing to underscore the importance of Vitamin D, it remains a key focus in maternal and child healthcare.


Aghajafari, F., Nagulesapillai, T., Ronksley, P. E., Tough, S. C., O’Beirne, M., & Rabi, D. M. (2013). Association between maternal serum 25-hydroxyvitamin D level and pregnancy and neonatal outcomes: systematic review and meta-analysis of observational studies. Journal of Nutrition, 143(5), 765-772.

Whitehouse, A. J., Holt, B. J., Serralha, M., Holt, P. G., Hart, P. H., & Kusel, M. M. (2012). Maternal serum vitamin D levels during pregnancy and offspring neurocognitive development. Pediatrics, 129(3), 485-493.

Vitamin D Supplementation during Pregnancy Part 2 NICHD/CTSA Randomized Clinical Trial (RCT): Outcomes.