by Laurel Blair, NTP
In speaking with others about vitamins and minerals itís become clear to me that there are a lot of misunderstandings around the nutrients in food and supplements. Over 50% of Americans currently take a multivitamin, and supplements of individual vitamins and minerals or formulas for specific health problems are also quite common. But myths about nutrients abound, even among the health-conscious. This article will address some of the most common myths, to bring clarity to the confusion surrounding vitamins and minerals.
Myth #1: Synthetic vitamins are the same as natural ones.
Truth: Natural vitamins from food are safer and more effective than synthetics. A good example of this is vitamin A. Synthetic vitamin A is well established as causing birth defects. To use the drug Accutane, which is basically a mega-dose of synthetic vitamin A prescribed for severe acne, women of childbearing age must agree in writing to use two forms of birth control and to have regular pregnancy tests before, during, and after taking the drug, due to the risk of severe birth defects. Many of the side effects of the drug resemble symptoms of vitamin A deficiency, suggesting that synthetic vitamin A may interfere with natural vitamin A pathways and functioning. One large study linked high consumption of preformed vitamin A during pregnancy with birth defects, but this study didnít distinguish between synthetic and natural vitamin A. It is safe to assume that the vast majority of the vitamin A consumed in this study was synthetic, since intakes of foods high in natural vitamin A have decreased significantly due to misguided fears of saturated fat and cholesterol. On the other hand, foods that are fortified with the synthetic vitamin A palmitate (including breakfast cereals, reduced-fat dairy products, and meal replacements) are common in the American diet, as are multivitamins and supplements containing the synthetic form.
Primitive societies enjoying freedom from degenerative diseases like heart disease and type 2 diabetes generally consumed amounts of preformed vitamin A that exceeded 10 times the modern RDA for vitamin A. This vitamin A was from food sources like liver, grass-fed dairy products, egg yolks from pastured hens, and cod liver oil. These people did not show any increase in birth defects from such high doses of vitamin A, and in fact were noted for their excellent bone structure, hardiness, and ease of childbirth. Several studies have also demonstrated that higher doses of vitamin A during pregnancy are not associated with an increase in birth defects, but these studies were not given media attention.
A similar scenario exists for vitamin C. Few people realize that ascorbic acid is the synthetic, isolated form of vitamin C, manufactured in a laboratory. In whole foods, vitamins exist as complexes containing multiple factors that are needed for proper absorption and utilization of the vitamin. In nature, vitamin C comes with bioflavonoids (sometimes called vitamin P) which help your body use the vitamin C. Consuming large amounts of isolated ascorbic acid as some people do can eventually lead to deficiencies in bioflavonoids and poor vitamin C utilization. Likewise, natural folate from green leafy vegetables and liver is perfectly safe and protects against birth defects, while the synthetic folic acid in most supplements and fortified foods has been linked to cancer. Nearly all B-vitamin supplements are synthetic. The natural versions are much more expensive, but they are also far superior and can be used with much lower doses. Cultured and fermented foods like yogurt and kombucha are good options for those who find natural B-vitamin supplements unaffordable.
A good rule of thumb for supplementation is to always avoid the synthetic forms of fat-soluble vitamins A, D, E, and K, which are stored in the body. Hereís a list of forms to avoid:
Vitamin A: retinyl palmitate, retinyl acetate
Vitamin D: D2, also called ergocalciferol
Vitamin E: any form of tocopheryl (as opposed to tocopherol), or any form of vitamin E that begins with dl- (like dl-alpha-tocopherol)
Vitamin K: K3, also called menadione
Myth #2: Beta-carotene is the same as vitamin A. You can get all the vitamin A you need by eating yellow or orange vegetables.
Truth: Beta-carotene is a precursor to vitamin A, and under optimal conditions your body can convert it into vitamin A. True preformed vitamin A is only found in animal foods, while carotenes are the forms found in plant foods. Beta-carotene can only be absorbed and converted to true vitamin A in the presence of bile salts, and bile salts are only released by the gallbladder when you eat something containing fat. In other words, if you eat a raw carrot by itself as a snack, you are not getting any vitamin A at all. One study showed that people eating a salad (consisting of spinach, romaine lettuce, cherry tomatoes, and carrots) with non-fat dressing didnít absorb any carotenes at all! To me, it seems dishonest to label foods as containing a vitamin when there are certain conditions that must be met in order to absorb that vitamin.
In addition to the requirement to eat carotene-containing veggies with a source of fat, there have been a lot of questions about the rate of conversion from beta-carotene to vitamin A. Early research indicated that the conversion rate was approximately 4:1 (4 units of beta-carotene to make 1 unit of vitamin A), but more recent studies have pointed to much lower conversion rates, even as low as 28:1! Unfortunately our nutrition labeling has not been revised to reflect this new research. For these reasons, it is important to include foods high in preformed vitamin A in your diet.
Furthermore, certain conditions drastically inhibit the conversion, including diabetes and thyroid dysfunction, which are both common. Zinc deficiency has a similar effect, and so do certain pharmaceutical drugs. People with these health issues need to consume preformed vitamin A regularly to prevent deficiencies. Natural preformed vitamin A is found in full-fat dairy products from grass-fed cows, liver, egg yolks, seafood, and cod liver oil.
Myth #3: Vitamin D levels should be at least 50 ng/mL for optimal health.
Truth: There is no convincing evidence that people need to push their vitamin D levels this high. Some organizations, including the Vitamin D Council, advocate for levels over 50 ng/mL, but the actual research indicates that levels should be at least 30-35 ng/mL. Higher levels may be beneficial, but they also could be harmful; we simply do not know yet! Until more research is done, I cannot recommend such high levels.
All of the current hype around vitamin D levels has convinced many people to supplement with higher levels of vitamin D. While vitamin D supplements can be beneficial and necessary for people with low levels, it is important to consider the interactions between different nutrients before supplementing with high doses of a single nutrient. In the case of vitamin D, it has a mutually beneficial relationship with vitamin A. As fat-soluble vitamins that are stored in the body, both of these vitamins have the potential for toxicity (although with vitamin A this is generally from the synthetic form). Fortunately, vitamins A and D each protect against the toxicity of the other. Vitamin A is only toxic when vitamin D is deficient, and vice versa.
In the past, mothers wisely gave their children supplements of cod liver oil, a true superfood that is high in omega-3 fatty acids including DHA and EPA, as well as being one of the best sources of both vitamins A and D. This practice has fallen out of favor due to concerns over the potential toxicity of vitamin A, but the vitamin D in cod liver oil is protective in this respect. Cod liver oil is an especially good supplement for the wintertime, when vitamin D production in the skin is diminished.
Myth #4: Whole grains are a good source of minerals.
Truth: While whole grains do contain more minerals than their refined counterparts, they also contain anti-nutrients like phytic acid which block mineral absorption. As the negative health effects of refined flour have become more and more apparent, many people have switched to whole grain products, believing them to be healthier. But whole grains (along with all nuts, seeds, and beans) contain phytic acid, an anti-nutrient that binds with minerals in the intestinal tract and prevents their absorption. Phytic acid is known to prevent absorption of calcium, magnesium, phosphorus, iron, and zinc. In order to get the benefit of the minerals they contain, grains and other seed foods must first be fermented through a sourdough process or soaked in a warm acidic solution for a period of time. This process activates the enzyme phytase which is naturally present in most grains and breaks down the phytic acid. Some grains like corn and most oats contain little phytase, so they need a slightly different treatment. In a future article, Iíll explain in more detail the problems with phytic acid and how to properly prepare grains to neutralize it.
Even if whole grains are prepared in these ways, their mineral content depends directly on the mineral content of the soil they are grown in. Conventionally grown crops are fertilized with only a few minerals, while others are severely depleted over years of production. This is especially true of magnesium and trace minerals. Itís best to buy organically grown grains, as they are generally grown on soil that is more completely fertilized.
Myth #5: Vegetable oils are a good source of vitamin E.
Truth: Consumption of refined vegetable oils (corn, soy, cottonseed, canola, sunflower, and safflower oils) has been demonstrated to increase the bodyís need for vitamin E. While vegetable oils appear on the label to be good sources of vitamin E, the reality is not so simple. Refined industrial vegetable oils have been processed in ways that render them rancid, full of free radicals which can damage your body. Free radicals are neutralized by antioxidants like vitamin E, which is probably why these oils increase the need for vitamin E (despite the fact that they may contain vitamin E). Unrefined, cold-pressed oils that are stored in dark bottles, refrigerated, and eaten raw may be good sources of vitamin E, but the vast majority of vegetable oils from the store are not.
Cold-pressed extra-virgin olive oil is a good option for those looking to increase their intakes of vitamin E. Olives are actually a fruit, not a vegetable, and olive oil is suitable for cooking at low temperatures. Buy olive oil that comes in dark containers to prevent rancidity.
Myth #6: It is safe to take large doses of a single vitamin or mineral.
Truth: Vitamins and minerals all interact with one another in a complex web of relationships. Taking high doses of one nutrient can sometimes deplete or increase levels of another. Vitamin C increases the absorption of iron, while calcium prevents absorption of magnesium when they are taken together. Excessive levels of iron can be a serious problem, especially for men. Copper and zinc need to be maintained in a proper ratio, and excess of one can cause deficiency of the other. Vitamins A and D each prevent toxicity of the other and should generally be taken together, while adequate zinc status is essential for the utilization of vitamin A in the body. These are just a few examples which demonstrate the problems that can result with excessive supplementation of a single vitamin or mineral. High doses of supplements are best used with the guidance of a health professional.
About Laurel: I'm very passionate about food and nutrition, partly because changing my diet has had a profound impact on my own health, and partly because I love to eat great food! I especially enjoy cooking using traditional preparation techniques, and I see cooking as a form of creative expression and a way to nourish myself and my family. I'm here to spread awareness of the amazing healing powers of whole foods and traditional diets. My insatiable appetite for learning about nutrition led to my recent certification as a Nutritional Therapist Practitioner. My intention is to share my knowledge with the community and support others in improving their health with real food. Visit my website (www.dynamicbalancenutrition.com) or follow me on Twitter at twitter.com/@Dynamic_Balance for more information. Blessings to all!