Vitamin D is essential for building strong bones, preventing osteoporosis, promoting heart health, and regulating blood pressure. The sun is the best and easiest way to get your vitamin D. Anywhere from 6 to 15 minutes of sun at a time (without sunscreen, but no more than 15 minutes) will provide enough to last the week (it’s fat soluble, meaning it’s stored in our fat cells for a longer period). If you’re missing out on the sun (aka it’s winter), the best food source of vitamin D is dairy—three servings will give you your entire day’s worth. If dairy doesn’t sit well with you, vitamin D3 supplements can offer the same benefits.
According to the 2015–2020 Dietary Guidelines for Americans, calcium is a major nutrient many people lack. It helps develop strong bones and regulate the circulatory and nervous system. Dairy products, fortified juices, and some plant foods (such as soybeans, bok choy, broccoli, and kale) contain calcium. Calcium supplements are also available. Take note: Plant sources of calcium are not as easy for the body to use, meaning you’d need to consume far more calcium via bok choy to get the same health benefits as a glass of milk.
Potassium is critical to muscle function, heart function, and blood pressure. Without proper potassium levels, it’s difficult to finish a workout due to changes in blood pressure. And your gains will be threatened, as potassium is linked to muscle growth and the breakdown of carbohydrates for energy. Fortunately, this nutrient is readily available from bananas, potatoes, citrus, dairy products, lean protein, soy products, tomatoes, and squash.
Magnesium is a mineral that regulates many biological processes in our body including protein synthesis, muscle and nerve function, blood glucose control, and energy production. If you’re lacking, you might be irritable, have irregular heartbeats, or experience muscle weakness. Magnesium is stored in bones and soft tissues, but a diet high in fat can decrease our body’s magnesium absorption. Skip the double cheeseburger and fries and try consuming green leafy vegetables, nuts, beans, and cereals to maximize the benefits that magnesium provides.
Iron deficiency, or anemia, makes our bodies struggle to carry oxygen through the body via red blood cells. Anemia can cause fatigue, weakness, and an overall decrease in physical performance. Often, menstruation can be a culprit in women. So to keep up your iron levels at that time of the month, or anytime, the most digestible form of iron (“heme iron”) is found in red meat. If you’re vegetarian, you can obtain iron from foods like cereal, beans, and some vegetables. An iron supplement can help as well, since vegetable forms of iron are harder to digest.
For proper growth, muscle repair, immune function, and energy production, zinc is your go-to mineral. Key foods to eat include peanuts, legumes, beef, pork, and shellfish. A lack of zinc can affect your metabolic rate (important for burning calories) and protein use. Be careful not to go overboard: Too much zinc can decrease the absorption of other vitamins and minerals while decreasing the amount of good cholesterol, HDL, in your body.
B vitamins are important for energy. Folic acid, also known as B9, is no exception. The need for folic acid increases from prolonged diarrhea, fever, stress, alcoholism, or pregnancy—a deficit can lead to birth defects or anemia. For optimal levels, consume meats, green leafy vegetables, potatoes, cereals, and fruit.
Vitamin A, as we know, is a key nutrient for vision. It comes in two forms: retinoids (found in animal products such as eggs, kidney, and liver) and carotenoids (found in yellow/orange fruits and vegetables like carrots and squash). Even though vitamin A is a fat-soluble vitamin and tends to stay in your body for longer, not getting enough can cause dry eyes, dry skin, or even night blindness.