|Dr. Lynn Cialdella-Kam is a research scientist at the Human Performance Laboratory-NCRC, Appalachian State University in Kannapolis, NC. She currently splits her time between nutrition and exercise science research and nutritional assessment in athletes. Dr. Kam's research is focused on enhancing recovery from exercise by flavonoids and other nutrients. She has experience working with elite swimmers and runners and pit crew teams. In her free time, she enjoys working out and competing with SwimMAC Masters swim team.|
I have this very distinct memory of being in my kitchen as a child with my Mom. She was about to give me some less than pleasant tasting medicine. As I made faces, she remarked “well, at least it is not cod liver oil”.
In her times, cod liver oil used to be the cure-all for everything. It was commonly prescribed to treat rickets in children. Old cod liver oil advertisements contain promises of curing everything from the common colds to consumption. Was this just a fad or is there something to cod liver oil?
Well, grandmother really knew best! Cod liver oil provides a good dose of vitamin D among other nutrients. Vitamin D has been a hot topic of research and news articles for many reasons. First, we are learning more and more about the role of vitamin D beyond bone health. Second, the prevalence of vitamin D deficiency in the U.S. is higher than initially believed. Third, experts are still debating what normal vitamin D blood levels should be for optimal health.
So, what role does vitamin D play? The most established role for vitamin D plays is bone health. Vitamin D facilitates the absorption of calcium from the gut into the blood. Calcium is thus available for bone remolding, which keeps bones healthy. Vitamin D’s other health roles are less established. It, however, has been implicated in cancer prevention, immune support and amelioration of diseases such as hypertension, multiple sclerosis, and glucose intolerance.
O.K., maybe it is time for a shot of cod liver oil – but before surfing the web for the best cod liver oil prices, it is important to understand what increases the risk of vitamin D deficiencies. First, many Americans do not consume enough vitamin D from food sources. The primary reason is there are few good food sources for vitamin D. In the U.S., the primary vitamin D sources are fortified products such as milk, cereals, and yogurts. Luckily our skin can produce vitamin D with adequate sunlight. If you limit your sun exposure or you are in the dead of winter, then skin production of vitamin D will not be sufficient. Other factors that can put you at risk for vitamin D deficiency are age, dark skin, fat malabsorption and obesity.
How much vitamin D should you be getting daily? It is recommended that adults consume 600 International Units (IU) of vitamin D daily. If your main source is fortified foods products, you are consuming approximately 40-140 IU per serving. Fatty fishes like salmon are a good source of vitamin D containing about 400-500 IU per serving. Only ˝ tablespoon of cod liver oil provides a full daily dose (600 IU per ˝ tablespoon). So, maybe a sprinkle of cod liver oil on your morning cereal may be just what the doctor order!
In the end, will you swim faster if your vitamin D levels are optimal? Quite likely – if you are providing your body what it needs nutritionally, you will be healthier overall. Feeling better usually translates into better swim performance. In terms of direct impact on swim performance, we still have much to learn. Researchers are beginning to explore how vitamin D may affect exercise performance and muscle health. Until then, include fatty fishes in your diet 2-3 times a week and select foods fortified with vitamin D. In some cases, a vitamin D supplement may be needed. My recommendation is to ask your doctor to check your vitamin D status before adding a supplement to your diet.