Dietary Supplements for Runners: Vitamins
Today’s guest post is contributed by Becca Addison, a registered dietitian with a specialist certification in sports nutrition (CSSD). Her resume includes working at Harvard University with varsity athletics. She is also my friend and former pro runner and training partner!
There are so many “nutritionists” and “health coaches” in an industry that is not strictly regulated, so I always recommend seeking the guideance of Registered Dietitian (R.D.)
I asked Becca “What kind of supplements (if any) are important for recreational runners?”
Dietary Supplements for Runners
Contributed by Becca Addison, RD, CSSD
Multi-vitamin
My typical recommendation for elite athletes, recreational runners, and non-athletes alike is that taking a multivitamin is up to you. I’m a strong proponent of the “food first” approach, but life gets busy and a multivitamin can be thought of as an “insurance policy.” Interestingly, in research, we see both neutral and positive health outcomes from taking a daily multivitamin - there’s zero consensus on whether or not it is truly needed. That being said, a multivitamin may be helpful during busy times or periods of intense training to fill in any gaps.
Something to keep in mind when taking a multivitamin:
Multivitamins do not always contain calcium or magnesium, because they are “bulky” materials (making them difficult to fit into a pill or gummy). If you’re taking calcium or magnesium for any reason, you’ll probably need to add them separately.
Vitamin D
Vitamin D is a controversial micronutrient because the cut-offs for what determines deficiency are not agreed upon by researchers. Sufficient blood levels (which range from 30 to 75 ng/ml depending on who you ask!) have been linked to better sports performance, but the strongest evidence occurs in relation to bone health. Vitamin D promotes bone growth and mineralization, and also increases calcium absorption.
The recommended daily allowance for the general population is 600 IU/day. Unfortunately Vitamin D is found in only a select few foods. Top sources include:
Fatty fish like salmon and tuna: 100-600 IU
Fortified foods (milk, juice, cereal): 100 IU
Egg yolk: 50 IU
Supplementing and Sunlight:
We can also synthesize Vitamin D in our skin from the sun. It only takes 10-30 minutes of midday sunlight per day, several times per week, to get the recommended amount. Interestingly, you cannot “overdose” on vitamin D from sunlight because of a feedback loop in our bodies that limits vitamin D synthesis. During the winter, the angle of the sun in certain parts of the world isn’t strong enough to produce Vitamin D in our skin! This includes locations above 37 degrees north of the equator from around November to April.
Because Vitamin D is not found in many foods and sunlight isn’t effective for many runners during winter months, I recommend a supplement from November to April. (Or June through August in the southern hemisphere.) Doses from 600 IU to 2000 IU per day of vitamin D3 are safe and have been shown to maintain sufficient blood levels. Unless you’ve been diagnosed with Vitamin D deficiency, stay away from higher doses.
An interesting study in 967 military recruits in the UK showed that both sunlight and oral intake are effective in maintaining adequate Vitamin D levels. The study took place in the dead of winter for 12 weeks, providing subjects with either 15 minutes of simulated-sunlight six times per week or a supplement of 1000 IU/day. At baseline, only 9% of men and 36% of women had sufficient Vitamin D levels (defined as above 50 ng/ml in this study). After the 12 weeks, 97% of subjects were above 50 ng/ml Vitamin D and none were deficient!
Regarding testing, The American Academy of Family Physicians doesn’t recommend regular testing of vitamin D. If you have a history of stress fractures, or you’re at risk of osteoporosis due to age, then talk to your doctor about a Vitamin D test.
Vitamin B12
Vitamin B12 helps keep your red blood cells and nervous system healthy. Vegans must supplement or consume foods fortified with vitamin B12 , since vitamin B12 is only found in animal products. The Institute of Medicine also recommends that adults over 50 consider a supplement or consume fortified foods such as cereals and plant-based milks, due to reduced absorption in the digestive tract within this population.
Vitamin C
Vitamin C is a very important antioxidant that protects against harmful free radicals in our bodies. It’s also used to synthesize collagen, a component of connective tissues including ligaments and tendons, which are important to keep strong and resilient for running.
What are “Free Radicals?”
Free Radicals are unstable atoms produced naturally in the body from everyday processes like metabolism and exercise, but they can build up over time and lead to oxidative stress which causes higher rates of illness and injury. Vitamin C balances out the free radicals by taking an extra electron!
The recommended daily intake for Vitamin C is around 80 mg per day, which is found in 1 cup of orange juice or a serving of colorful fruits and vegetables - broccoli, bell pepper, or brussels sprouts to name a few.
Ever find yourself under the weather more often when increasing your training volume? There is some evidence that consuming higher amounts of Vitamin C reduces incidences of colds in people exposed to excessive physical stress. More isn’t always better though, since high doses simply result in more vitamin C being peed out in your urine.
It’s best to get your vitamin C from fruits and vegetables, but if you want to take a moderate dose (500-1000 mg) in addition to your fruits and veggies to get you through a hard training block, that’s fine too!
Avoid Contamination in your Supplements
Make sure your supplements are third-party tested! Supplements aren’t regulated by the FDA, and are often contaminated. Look for NSF Certified for Sport, Informed-Sport, or USP verification on the bottle.
Some third-party tested brands I recommend are:
Thorne
Klean
Ritual
Care/of
Smarty Pants
Garden of Life
Rainbow Light
Olly
Centrum
Mega Foods (especially for Iron)
Nature Made