Vitamins & Minerals: Should you take supplements?

No two diets are exactly the same, and they shouldn't be. Everyone has different food preferences, energy needs, and nutritional requirements. A marathon runner requires a very different diet from a gymnast, a sedentary office worker, and an individual who just had a heart attack. A marathon runner training 80-100 miles a week at altitude requires more than a marathon runner doing 40-50 miles a week at sea level. Even two individuals recovery from a heart attack will have different diets depending on their level of activity, medications, medical history, and weight goals. 

Although diets and calorie needs may vary tremendously, there are certain vitamin and mineral requirements that need to be met in every population. Vitamins A, B, C, D, and E as well as minerals including calcium, iron, magnesium, sodium, and potassium are all essential for our health and wellbeing. There are multiple ways to get these nutrients including various food sources as well as supplements; however, some sources are much better than others. Ideally, all of our energy and nutritional needs would come from whole, real foods: fruits, vegetables, dairy, meat, seafood, and oils. Vitamins and minerals in real foods are absorbed the best and exist in the proper balance. The problem is we may not have adequate access to the right foods, we may choose a special diet such as vegetarian, or we may have food allergies such as lactose intolerance. This is where supplements play a role. I try to eat as much real food as I can before reverting to a supplement. Wouldn't you rather eat some fruit salad instead of taking a vitamin C supplement? 


Today I am going to focus on a few nutrients I find many people have a hard time obtaining enough of: vitamin D, calcium, and iron. These are especially important to endurance athletes, as well as the general public. 

Vitamin D

Vitamin D is required for calcium absorption, bone health, muscle function and strength, inflammation control, and good immunity. 

Food sources of vitamin D are very limited. It is in fatty fish, egg yolks, and fortified milk and cereal products. The other source of vitamin D is sunlight, which is great if you live in Florida, but not so great in you live in northern areas of the U.S. from October to April. 

The daily recommended amount of vitamin D is 600 IU for males and females up to 70 years old. The minimal amount for people ages 71 and above is even higher, 800 IU, because we lose your ability to make vitamin D from the sun as we age. 

Since food sources of vitamin D are slim and I live in the Northeast where it is cloudy/snowy most days, I recently chose to start a Vitamin D supplement that provides me 1000 IU during the winter months. Here is my vitamin D supplement on top of a sports nutrition book and the nutrition facts of milk showing the added vitamin D:


Most of us know calcium is essential for building strong bones and bone health. The majority of our bone mass is built by age 25 to 35, but we still have to focus on maintaining what we have after that time. 

The best food sources of calcium are dairy including milk, yogurt, and cheese. There is also calcium in leafy greens such as kale and bok choy, broccoli, beans, and fortified orange juice.

The daily recommended amount of calcium is 1000 mg for men ages 19+ and women ages 19-50. For women over the age of 50, the recommended amount increases to 1200 mg due to body changes that cause greater bone loss. 

Most food labels provide a percentage of daily value. A cup of milk or yogurt is typically 30% of your daily needs. This can be converted to about 300 mg. 

I enjoy dairy, so obtaining enough calcium is not a challenge for me. We have meals and snacks such as yogurt and granola, oats made with milk, milk and cereal, pizza, grilled cheese, and cheese and crackers regularly. A supplement should be considered if your food intake does not suffice (i.e. less than 3 servings of dairy daily) or if you are at a high risk for bone loss (osteopenia/osteoporosis). 

Here is our hearty yogurt and cheese supply:



Iron is essential for energy and metabolism. It plays a key role in transferring oxygen in our blood and getting oxygen into our muscles. A lack of iron results in iron-deficiency anemia causing fatigue, exercise intolerance, and performance impairment. 

The best food source of iron is red meat. It is also found in dark poultry, shellfish, lentils, beans, spinach, and fortified cereals and grains. Iron is better absorbed when eaten with vitamin C, so try to have iron rich foods with things like peppers or oranges or strawberries. 

The daily recommended amount of iron for females ages 19-50 is 18 mg. For females ages 50+ and males ages 19+, the recommendation is 8 mg daily. For an idea, 3 oz of cooked beef has 3.5 mg iron.

We try to have red meat 1-2 times per week, and we also consume lots of beans. Dishes such as chili, hamburgers, spaghetti with meat sauce or meatballs, rice and beans, and lentil soup are frequently on our menu. I have never had my iron levels tested, but it would be something I would like to get done in the future to check. If you are a vegetarian, do not like beans, and you are a female age 19-50, an iron supplement would be important for you to consider. 

Always ask your doctor before starting or changing a supplement. Certain vitamins and minerals can be toxic in very high doses.