A Forgotten Hero? Vitamin A to the Rescue

Vitamin Who? In recent years, we haven’t heard much about Vitamin A. Unfortunately Vitamin A deficiency is internationally profound and widespread. You may have read about efforts to prevent early childhood death from infectious disease in third-world countries (for which Vitamin A has been a tremendous blessing). But otherwise, conventional medicine media has little to say about this critical nutrient. While overt, life-threatening Vitamin A deficiency is rare in our society, most of us are unaware of the impact (and common risk) of having suboptimal Vitamin A.

Both a fat-soluble nutrient and a hormone (like Vitamin D), Vitamin A plays a wide range of key functions in the body. It is especially critical for the ongoing health of surfaces which line the body which are called epithelial cells (e.g. our skin, respiratory tract, GI tract, urinary tract). It is also crucial for good vision (hence the old adage of eating carrots for healthy eyes!), and insufficiency can lead to impaired vision or night blindness. Vitamin A supplementation has also been shown to improve eczema, lower the incidence of kidney stones, protect against the formation of stress-related ulcers, alleviate dry skin or brittle nails, and reduce the incidence of ear infections in children.

Most important for our new year’s outlook, Vitamin A plays a major role in immune system strength. (For the technically inclined, this is achieved in particular by increasing our T-regulatory cells and balancing effector T cells. Vitamin A is also required for secretory IgA production and helps regulate the very inflammatory cytokine IL-17).  Insufficient levels can lead to loss of immune tolerance and increased susceptibility to infections, allergies, and auto-immune illness. Low Vitamin A is often found in diabetics, alcoholics, and those with auto-immune disease such as Crohn’s Disease.

Vitamin D is also critical for immune system regulation, and many people supplement with it in the months when New Englanders cannot make any Vitamin D from the sun (from October through April). You simply cannot get enough Vitamin D from food during these months: we are designed to get it from warm sunlight! But here’s something that might really surprise you: Vitamin D and Vitamin A actually bind to the same final cellular receptor in the body. So increased uptake of one can cause a (relative) deficiency in the other if your levels aren’t balanced. I recommend getting both checked this winter. Both are simple blood tests, and they are readily available from just about any physician. Make sure you ask for your specific data results (not just a letter saying your levels are “fine”). You will want to be in the upper half of the reference range for both.

Why are we deficient? Most multivitamins today include only plant-based precursors to Vitamin A, usually beta carotene. We know clinically that, at best, only 40-60% of beta carotene from plant sources is absorbed. Unfortunately, it’s also estimated that as much as 50% of the population is poor at (or incapable of) converting carotenes to true Vitamin A. Research shows there is extreme genetic variability in our conversion capability. This critical conversion happens in the lining of your intestines and is also dependent on several nutrient co-factors, especially zinc and iron. Thus those with anemia or zinc deficiency (common!) may struggle. Your Vitamin A conversion will also likely be significantly impaired if you have gastrointestinal issues such as food allergies/sensitivities, parasite infection, bacterial overgrowth (dysbiosis), digestive enzyme deficiency, gallbladder issues, celiac disease, or fat malabsorption. Complicated GI disorders are a focus area in my client practice, and unfortunately I see these circumstances every day. In addition, conversion of beta carotene to the active form of Vitamin A is regulated directly by T3 thyroid hormone. As I’ve shared before, we have an epidemic of subclinical hypothyroidism (that is NOT, by the way, being treated well with the conventional protocol of synthetic T4-only medications e.g. levothyroxine. Many people who take T4-only meds are still deficient in T3 (the only accurate way to check this is to assess your “free T3″ levels). As you can see, Vitamin A sufficiency can be a challenge!

Another barrier to Vitamin A sufficiency in our culture is the mainstream health media’s inappropriate fear-mongering about saturated-fat-containing foods. In fact, natural, healthy, nutrient-dense foods such as organic and grass-fed whole eggs, beef, butter and cheese are excellent sources of fully-formed Vitamin A. And yes, you need to eat the egg yolks (that’s where all the nutrients are!). Vitamin A is also high in oily fish like mackerel. Prior to this media push in the 1980s, many American families also used to have a ritual of eating calf’s-liver-and-onions once every week or two, an amazingly nutrient-dense meal featuring huge amounts of easy-to-absorb iron, zinc, copper, selenium, folate, Vitamins B12, B6, B2, B3, B5 and Vitamin A. This traditional meal may not appeal to everyone, but there’s no reason to be afraid of it as long as we are choosing high-quality food sources.

Beyond food, to boost your immune system (especially if you don’t eat much of the foods above), I recommend 5000 IU daily of fully-formed vitamin A (i.e. one of the retinoids like retinol palmitate vs. just beta-carotene). Be sure to take it on a full stomach after a fat-containing meal. If you struggle with any of the ailments I’ve mentioned, you may want to get your levels tested and try a higher dose of 10,000 IU/day (the tolerable upper intake level recommended by the Institute of Medicine) for a few months. Contrary to popular myth, true Vitamin A toxicity is extremely uncommon and has been found to occur in adults only at intake levels of 50,000 to 100,000 IU/day. I suspect isolated “toxicity” incidents may actually be caused by an imbalance of Vitamin A and D that I mentioned earlier, especially given the high incidence of Vitamin D deficiency in New England. Common early signs of too much Vitamin A include itchy skin, headaches, and nausea which resolve quickly after reducing intake.

In summary, our immune system needs support during the winter months. You do not have to get a cold or an upper respiratory infection every year!  My recommendation for most is a combination of Vitamin D (minimum 2000 IU/day D3 is safe for almost all), Vitamin A from food or supplement, a probiotic, and zinc (20mg/day is safe for all – don’t get the carbonate form) supplementation along with a diet rich in Vitamin C and K in the form of dark leafy green vegetables.  Choose to be well!