Among the micronutrients, vitamins are well known, but not well understood by consumers in general.
Most people probably think of a bottle of supplements when considering the role of vitamins in their lives, but the best vitamin sources are whole foods. In fact, there is much more bang for the buck by getting vitamins from foods. Individual nutrients lose value by themselves – a prime example of the whole being greater than the sum of the parts. Many nutrients work optimally only when accompanied by cofactors, such as water, other vitamins or fats, among others.
Vitamins can be classified into two groups: water-soluble and fat-soluble. The water-soluble vitamins, namely B and C, are flushed from the body when consumed in excess and must be replenished regularly. The fat-soluble vitamins, A, D, E, and K, can be stored in fat. The bonus is there is the ability to save a bit for times of need, but the negative is the potential for excess accumulation to the point of toxicity.
Luckily, both of those potential problems – deficiency and toxicity – become rarer as a person’s whole-foods diet becomes more varied and nutrient-dense. Vitamin D toxicity, for example, is a greater risk when the Vitamin D is taken in supplement form amidst a Vitamin A deficiency. It’s all about balance, and the best balance comes from whole foods instead of supplements.
Fat-soluble vitamins are particularly interesting because of their need have dietary fats as cofactors. This is the biochemical reason for topping a salad with dressing – the dark leafy greens are a notable source of fat-soluble vitamins, but fats must be consumed along with them to allow for absorption. Within the context of a low-fat diet, deficiencies in fat-soluble vitamins become a real concern. For the greatest health benefits, have your greens and eat fats too!
Vitamin A is critical in many body functions and processes including reproduction, eye function, skin health, and bone and tooth construction. The earliest signs of deficiency are night blindness and small bumps on the back of the arms.
If either of these symptoms arises, it is important to assess both Vitamin A intake and the ability to digest fats. A deficiency will arise if Vitamin A intake is low, but can also result from faulty fat digestion. When fats are poorly emulsified, due to impaired liver and gallbladder function, or a missing gallbladder, the fats essential for Vitamin A absorption will not be available.
The best Vitamin A sources include liver, egg yolks, and full-fat milk and butter. Beta-carotene is found in orange vegetables, such as carrots, pumpkins, sweet potatoes, apricots, and cantaloupe, as well as in leafy greens. This Vitamin A precursor must be converted to Vitamin A. That process requires Vitamin E, fatty acids, adequate thyroid function and good blood sugar control.
Vitamin D is both a vitamin and a hormone. Its most important function is the regulation of calcium for bone strength and health. Indeed, Vitamin D deficiency can cause weakened bones through dysregulated calcium.
The best source of Vitamin D is through the conversion of cholesterol in the skin by exposure to sunlight. Unfortunately for Alaskans, sunlight can be hard to come by for most of the year. Even tanning beds do not typically provide the correct type of UV light that supports that conversion – tanning beds usually emit UVA rays, but UVB is needed to make Vitamin D.
In these northern climates, a good supplement is usually required. Food sources are similar to those for Vitamin A: liver, egg yolks, full-fat dairy.
Vitamin E mainly functions as an antioxidant – basically neutralizing toxins from our food and environment. Today’s lifestyles generate more toxins than in the past, so Vitamin E is probably more quickly depleted. Adequate intake is protective against cancer and heart disease.
Again, this vitamin is found in liver, egg yolks, and full-fat dairy, but the best sources are nuts, seeds and some leafy greens.
Vitamin K is starting to gain momentum as a nutrient of particular interest. It is essential for blood-clotting but also ensures the appropriate transport of calcium. It shuttles calcium from the blood and deposits it in the bones, rather than along the arteries or another dangerous site in the body.
Our good friends liver, egg yolks, and full-fat dairy are sources, but so are dark, leafy greens and kelp. The most bioavailable source is that made by your own gut bacteria in the large intestine. To maximize production, it is important to care for your microbiome by avoiding excess processed foods and antibiotics. Also, be on the lookout for symptoms of dysbiosis such as yeasty flare-ups, or bad smelling breath or bowel gasses.
Many people look for nutritional security in a multi-vitamin. These are often composed of synthetic versions of vitamins, which fail to meet the body’s biochemical needs. The best insurance policy is a diet packed with appropriately raised animal products, and nutrient-rich, colorful and varied plant foods.
Enig, M. (2000.) Know Your Fats: The Complete Primer for Understanding the Nutrition of Fats, Oils, and Cholesterol. Bethesda Press: Bethesda.
Haas, E. (2006.) Staying Healthy with Nutrition. Celestial Arts: Berkeley.
Sara Kennedy is a certified Nutritional Therapy Consultant. She lives fitness, nutrition and wellness – and wants to help save lives and change the world’s view on health and nutrition. Learn more about Sara and her plans at thriveak.com To reach her, email email@example.com