Vitamin A can be a hot topic in pregnancy. While some argue that many mamas aren’t getting enough or the right kind, others point to research that too much can be harmful. Like many debates, there is validity to both sides.
So what’s the optimal balance? What type and how much should you have? And why do you and baby need it in the first place?
We at Needed thoroughly researched all of these big questions when establishing how much Vitamin A to include in our prenatal, and we continue to follow emerging research to be sure we’re incorporating new science into our formulas whenever appropriate. This blog is intended to share with you what we know, and why we do what we do.
Why Vitamin A is Needed
We’ll start with the why - why is Vitamin A needed during pregnancy and while breastfeeding anyway?
Both mama and baby need Vitamin A in pregnancy. Mama needs Vitamin A to support her immune and thyroid function, as well as healthy skin and vaginal tissues. Vitamin A is even essential in preconception and early pregnancy as it is necessary for the production of estrogen and progesterone which support embryo implantation and pregnancy viability.
Baby needs Vitamin A to help regulate gene expression and support the development of the heart, eyes, ears, limbs, and immune system. Insufficient Vitamin A can lead to fetal malformations, including improperly formed craniofacial structures, limbs, and internal organs. Vitamin A can also support pregnancy outcomes, including carrying baby to full term and baby’s adequate birth weight.
Both mama and baby need Vitamin A in the postpartum period as well. Even if mama isn’t breastfeeding, Vitamin A continues to support immunity and thyroid health throughout postpartum. Postpartum thyroiditis is common and uncomfortable, but treatable when properly diagnosed. Vitamin A supplementation is crucial to supporting a healthy thyroid. Many mamas enter postpartum depleted in Vitamin A if they only supplemented with beta carotene throughout pregnancy and did not eat liver (the richest food source of Vitamin A). If this is the case, rebuilding stores with preformed (more on this later) Vitamin A in postpartum is wise.
If mama is breastfeeding, breast milk is an important source of Vitamin A for baby. The amount of Vitamin A in breastmilk is directly related to the amount of Vitamin A that mama consumes through food and supplements.
As Vitamin A is crucial to infant growth, immune system development, and brain and vision development, it’s important that mama gets enough. Unfortunately, research shows that it’s common for mamas to not have enough - an estimated 46-58% of women do not have sufficient Vitamin A in their breast milk.
This is due in part to many prenatal vitamins including only beta carotene which doesn’t convert well, and in part due to the extremely high demand that babies have in the first 6 months of their life. Incredibly, during this time, babies receive 60 times the amount of Vitamin A that they received during the entire 9 months of pregnancy in order to support development and build their liver stores of Vitamin A. This demand starts right away, and in fact, colostrum is higher in Vitamin A than mature milk.
Types of Vitamin A
Another debate and source of confusion that exists is over the type or form of Vitamin A. The two types include Retinol (Preformed Vitamin A), and Carotenoids (Provitamin A):
1. Retinol (Preformed Vitamin A)
Retinol, or Preformed Vitamin A, exists exclusively in animal foods. It is referred to as Preformed Vitamin A, because it already exists in an active form that is easily used by the body.
Good food sources include beef or chicken liver, cod liver oil, eggs, mackerel, salmon, salmon roe, and butter. On supplements, look for the ingredient Retinyl Palmitate.
2. Carotenoids (Provitamin A)
Carotenoids, or Provitamin A is found in plant foods. Good sources include sweet potatoes, carrots, spinach, pumpkin, cantaloupe, red peppers, and broccoli. However, these foods can’t be considered a substitute for foods with preformed Vitamin A. That’s because your body must convert Provitamin A into Retinol in order to be usable, and the efficiency and effectiveness of this conversion is quite low in many women.
Research presented in the American Journal of Clinical Nutrition showed that the most commonly discussed Carotenoid, Beta Carotene (found in foods like carrots and sweet potatoes) converts at consistently low rates that vary depending on a number of factors, ranging from 3.6-28:1 by weight. In other words, it takes 28 μg of Beta Carotene to equal 1 μg Retinol!
This may lead you to think--why not just load up on orange veggies to get enough Beta Carotene to convert a reasonable amount? Unfortunately, that approach would actually backfire, as the more Beta Carotene you eat, the less you convert to Retinol.
Can Vitamin A Be Dangerous?
As with many nutrients, there are risks associated with both too little and too much Vitamin A. But, unfortunately, fear around the safety of Vitamin A in pregnancy has led many women (and some supplement companies) to steer clear of it entirely, or to include only the Beta Carotene form. To help you make an informed choice, let’s unpack what we know about the safety of Vitamin A, and how much is too much.
Unfortunately, data on the teratogenicity of Vitamin A, that is, the ability of it to disturb the development of the embryo or fetus, is limited. This is because human clinical trials are not ethically possible. Therefore, we need to rely on existing observational studies, epidemiologic trials, and on knowledge of Vitamin A metabolism and functions, which is largely derived from animal studies. The information we do have clearly shows that the teratogenicity of Vitamin A is biologically and physiologically possible, but due to the high levels needed to cause issues, it happens fairly infrequently.
An impressive study in the New England Journal of Medicine followed over 22,000 women over three years to try to identify the level of Retinol at which teratogenic effects occur.
It found an apparent threshold around 10,000 IU per day of supplemental Preformed Vitamin A. The study also identified that the increased frequency of defects was concentrated among the babies born to women who had consumed high levels of Preformed Vitamin A before the seventh week of gestation. Furthermore, the study estimated that among all babies born to women who took more than 10,000 IU of supplemental Preformed Vitamin A per day, about 1 infant in 57 had a malformation attributable to the supplemental dosage.
We include a very safe and supportive dose of 750 mcg or 2,500 IU of Retinyl Palmitate, the active form of Vitamin A. We utilize an amount that is far below the level at which potential teratogenic effects have been identified, and that is sufficient to support both mama and baby through pregnancy and lactation. In addition to Preformed Vitamin A, we also include 750 mcg of Beta Carotene to round out our dosage.
Mamas do sometimes wonder if it's safe to consume liver and other food-based forms of Vitamin A in addition to our Prenatal Multi. The answer is absolutely, yes. Recall, the research on the upper safety limit of Preformed Vitamin A looked at supplemental A, not food-based sources. It is highly unlikely that consuming a standard amount of liver or dairy products would come anywhere close to reaching the 10,000 IU/day recommended limit, even in combination with our 2,500 IU dosage.
We hope you feel empowered in knowing more about the safety and necessity of this critical nutrient, and also confident in the form and dose we’ve included in our Prenatal Multi.