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By Sarah Dillingham, Contributing Writer
Every pregnant woman and healthcare provider knows that adequate nutrition is vitally important during pregnancy, as key nutrients are crucial to the support of all stages of fetal development. In particular, a large body of evidence has linked folate deficiency with neural tube defects. However, symptoms of pregnancy such as exhaustion and nausea sometimes make it difficult for pregnant moms to get adequate nutrition through diet alone, so most healthcare practitioners routinely prescribe prenatal supplements to all their patients.
This practice can be problematic since many healthcare practitioners don’t differentiate among brands of prenatals, and some synthetic supplements can actually do more harm than good. Today we’ll take a look at why choosing a prenatal carefully is important, which brands are least harmful, and how pregnant women can cover all nutritional bases with diet if they choose to forgo supplementation.
Prenatal Vitamins: Decoding Folate VS Folic Acid
All synthetic forms of nutrients can tax the liver and kidneys, organs which are already under stress during pregnancy. Naturally occurring nutrients in foods also commonly exist with co-nutrients which facilitate bioavailability and absorption, and not all of these co-factors have likely been identified – they are likely missing in vitamin supplements.
Perhaps the most problematic of all nutrients included in prenatal supplements is one of the most important for pregnant mothers: Vitamin B9, which exists in several forms. Folate is the naturally-occurring bioavailable form in many foods such as leafy greens and liver. Folic acid is the synthesized compound pteroylmonoglutamic acid, used in vitamin supplements and as a mandatory food additive since 1998.
Folic acid and folate are not equivalent in safety or bioavailability. While naturally occurring folate is absorbed through the small intestines for conversion to the bioavailable form of B9, tetrahydrofolate (THF), synthetic folic acid initially undergoes reduction and methylation via the liver, where it is converted to THF via the enzyme dihydrofolate reductase. This alternate methylation pathway is potentially troublesome for everyone, but particularly pregnant women, whose liver function is already burdened.
Dihydrofolate reductase activity is relatively low in the liver, which may be why unmetabolized folic acid has been identified in the bloodstream of those who consume folic acid supplements and fortified foods. Even more troubling for pregnant women, excess folic acid consumption has been widely associated with numerous forms of cancer.
The most concerning aspect of folic acid supplementation is perhaps its implications for approximately 60% of the human population, who carry a mutation in one or more copies of the methylenetetrahydrofolate reductase (MTHFR) gene. The MTHFR gene is responsible for producing the enzyme of the same name, mentioned above, which – among other functions – converts all forms of folate into the form directly bioavailable at the cellular level: levomefolic acid or l-methylfolate (5-MTHF).
People who have one mutated copy of the MTHFR gene (heterozygous) can convert approximately 60% of their folate intake, while people with two mutated copies (homozygous) can convert approximately 30% of their folate intake. So for this population of people, ingesting the most bioavailable forms of B9 either through diet or supplements is extremely important.
Pregnant women or those trying to conceive may choose to be tested for MTHFR mutations, either through their doctor’s office or www.23andme.com. Knowing their MTHFR status may help pregnant women decide whether they should include supplements if their diet is already very rich in folate. More information is available at www.mthfr.net.
Which Folate Supplement to Choose
Women who choose to take a prenatal should take care to check the label carefully and confirm the supplement contains only bioavailable folate, and not folic acid. It’s also wise to read the labels of any processed foods and avoid those containing folic acid.
The following supplements contain only bioavailable folate:
Other products with bioavailable folate we haven’t found yet may be on the market, but we can vouch for these two. Functional medicine specialists familiar with the needs of pregnant mothers and those with MTHFR mutations can provide sound recommendations. Also see more information about prenatal supplements here.
The Nutrients You Really Need
Nutrition science, particularly regarding nutritional supplementation, is an emerging discipline with many avenues yet to pursue and many questions yet to be answered. Some pregnant women may feel most comfortable obtaining their nutrients through adequate diet, while monitoring their serum nutrient levels regularly via their healthcare provider.
Below are the recommended daily allowances for pregnant women:
|Vitamin A||770 mcg|
|Vitamin C||85 mg|
|Vitamin D||15 mcg|
|Vitamin E||15 mg|
|Vitamin K||90 mcg|
|Vitamin B6||1.9 mg|
|Vitamin B12||2.6 mcg|
|Pantothenic Acid||6 mg|
Editor’s Note: Keep in mind that the RDA is the recommended daily requirement defined by the FDA, and not necessarily the optimal amount needed.
These RDAs can be met with a variety of combinations. The USDA National Nutrient Database is a useful tool to search the nutrient content of thousands of foods.
For instance, 400 grams of lightly boiled and drained spinach, about 14 ounces, covers many nutritional bases and can be snacked on throughout the day or added to smoothies, etc. (Lightly boiling the spinach removes phytic acid and goitrogens, which can block nutrient absorption.) This quantity of spinach actually provides well over the RDA of many nutrients, but is perfectly safe to consume every day or every few days, as dietary nutrients don’t include the by-products of synthetic supplements and excess unused nutrients are easy for the body to excrete. This serving of spinach provides the following:
The Vitamin K content is particularly notable, since the assumption of inadequate dietary Vitamin K is a common justification for administering the Vitamin K shot to newborns directly postpartum.
Pregnant mothers can easily consume 114% of their daily iodine requirement with a rounded teaspoon of organic dulse flakes, which are mild-flavored and can be sprinkled onto other foods.
Every RDA may not need to be met every day, as long as the average consumption meets or exceeds the requirement. Many combinations of daily menu items provide a bounty of nutrition and will cover most bases – the low values can be compensated for the following day.
The following is a sample menu which covers the nutritional needs of pregnancy well:
|Food||Serving Size (g)|
|Yogurt (full fat, grass-fed)||383|
|Cream, Heavy Whipping (grass-fed)||206|
|Chocolate (80% cocoa content)||57|
|Egg (organic, free-range)||125|
|Celtic Sea Salt||1.4|
|Chicken Thigh (skinless)||180|
|Tomato Paste (cast-iron cooked)||28|
|Cranberry Juice (Not from concentrate, unsweetened)||18|
|Cauliflower (cooked, boiled, drained)||201|
|Celtic Sea Salt||1.8|
|Spinach (cooked, boiled, drained)||200|
|Salmon (wild, raw)||50|
Either nutrition or careful supplementation can be effective in meeting the nutritional needs of pregnant women, and healthcare providers should support them in the option with which they’re most comfortable.
How do you get the nutrients you really need in pregnancy?
Trying to get pregnant? Get our pre-conception plan -- including the diet tips and key supplements you need for a healthy pregnancy!