As coaches, we often receive questions about vitamin supplementation. While in some situations vitamin supplementation may be warranted, more often than not you can reach the appropriate Dietary Reference Intake (DRI) by way of the foods you choose! This I not an extensive list of the vitamins, but below are some of the ones we get asked about most frequently within our work.
VITAMIN A: DRI FOR MALES: 900 mcg/day; FEMALES: 700 mcg/day
Function: Vitamin A is most notably known for its relation to vision, but this vitamin also aids in immune function, is used for skin conditions, and supports reproduction. Within the human diet, 2 forms of Vitamin A can be found; retinol and carotenoids (orange/red).
Deficiency may result in: reversible night blindness, dry eyes, scaly skin (hyperkeratosis), keratin buildup in the eyes which are known as Bitot’s spots, and loss of vision.
Toxicity may result in: dry skin, abdominal pain, vertigo, and jaundice
Sources: sweet potatoes, carrots, peppers, spinach, and fat-free milk
VITAMIN C: DRI FOR MALES: 90 mg/day; FEMALES: 75 mg/day
Function: While Vitamin C is best known for its role in preventing scurvy, it is also required for collagen production. Vitamin C may help improve immune function and prevent infection. Additionally, this vitamin functions as an antioxidant and can increase the absorption of non-heme iron in the diet!
Deficiency may result in: scurvy, poor/delayed wound healing, may decrease copper absoption.
Toxicity may result in: Diarrhea and the formation of kidney stones
Sources: Citrus fruits, peppers, broccoli and brussel sprouts
VITAMIN D: DRI FOR MALES AND FEMALES AGES 9-70: 15 mcg/day
Function: Vitamin D is needed for healthy bones and teeth. Vitamin D can also play a role in neuromuscular and immune function as well as in reducing inflammation.
Deficiency may result in: In infants, rickets can develop. In adults, oteomalacia can develop.
Toxicity may result in: High levels of calcium in the blood, anorexia, and nausea/vomiting
Sources: Sunlight, cod liver oil, tuna, egg yolks, salmon, and cheese.
Vitamin B12: DRI FOR MALES AND FEMALES: 2.4 mcg/day
Function: Critical for red blood cell formation, can help prevent pernicious anemia, needed for maintenance of the nervous system, DNA synthesis, and growth.
Deficiency may result in: Macrocytic, pernicious anemia. Vegans will need to consume B12 from fortified foods and/or as a supplement.
Toxicity may result in: N/A
Sources: Vitamin B12 is found primarily in animal products. Some common examples are organ meats, dairy, eggs, fish, and beef.
There is a magnitude of opportunities within the diet to obtain all of the vitamins that you need and in the appropriate amounts. If you feel that you may be deficient in any of the above vitamins, it is important to consult with your physician and explore getting labs drawn in order to identify if there is in fact a deficiency present before jumping into supplementation!