Vitamin D
One of the great mysteries in human biology is the fact that most human breast milk is deficient in Vitamin D. How could nature overlook such an important nutrient in the "perfect food"? One possibility is that most human breast milk is deficient in vitamin D because many mothers (up to 95%) are deficient in vitamin D. Many studies support this hypothesis.
A large amount of research suggests that some of the damage done by Vitamin D deficiency is done in-utero. Much of that damage may be permanent, that is, it can not be fully reversed by taking Vitamin D after birth.
Incidence of Gestational Vitamin D Deficiency is very high (Lee, 2007). Prenatal vitamins (which usually only contain 400 IU of Vitamin D) have little effect on the incidence of deficiency (Bodnar, 2007).
Maternal effects include:
Women with levels below 15 ng/ml are four times more likely to have a Cesarean section than women with higher levels (Merewood, 2009).
Women with 25HD levels less than 15 ng/ml had a five-fold (5 fold) increase in the risk of preeclampsia (Bodnar 2007).
Women with low 25HD levels are almost 3 times more likely to develop gestational diabetes (Zhang, 2008).
Pregnant women with the lowest 25HD levels are almost twice as likely to get bacterial vaginosis during pregnancy (Bodnar 2009).
Effects on fetus:
Research has been done to back up the theory that maternal Vitamin D deficiency adversely "imprints" the fetus, making infants more liable for a host of adult disorders (McGrath, 2001).
Evidence suggests a role of maternal Vitamin D deficiency during fetal brain development in the incidence of schizophrenia (Kinney, 2009), autism and mental retardation.
Newborn lower respiratory tract infections and pneumonia are thought to be associated with pediatric Vitamin D deficiency (Karatekin 2009, Walker, 2009).
Low infant birth weight (Scholl, 2009)
Adequate Vitamin D has been shown to reduce incidence of type 1 diabetes in children.
Neonatal seizures (Fleishman, 1978), heart failure (Maiya 2008), also epilepsy, brain tumors, asthma.
Tip for clinical practice:
Consider checking a 25-hydroxy-Vitamin D (25HD) level on all of your pre-conception, pregnant or lactating patients, and consider supplementation for deficiency
Pre-Conception: Check 25HD levels, and aim to supplement your patients to achieve a level > 30
Pregnancy: Current guidelines limit Vitamin D supplementation to 1000 IU daily. This dosage may not be sufficient, depending on the patient's race and level of sun exposure. Many experts around the world recommend dosages higher than 1000 IU to patients to achieve adequate levels.
Lactation: Studies suggest that supplementing lactating women with up to 4000 IU Vitamin D3 daily can create sufficient 25HD levels for both mother and infant, without supplementing the infant. Current AAP recommendations are to supplement exclusively breastfed infants with 400 IU D3 daily.
Resource:
(Brendan Landis, Sunshine California Sunshine Ocean
Sunshine Ocean California, flickr. CC: BY-SA 2.0. Downloaded on August 3, 2009.)