Supporting Your Mind and Body

Vitamins, Minerals, Supplements

Person with short hair standing in a kitchen, drinking a glass of water, with tattooed arms and wearing a dark top.

Support Your Body With the Right Vitamins, Minerals, and Supplements

Eating well is one way to support your body through treatment and beyond, but sometimes food alone isn’t enough. You may already know that some vitamins stay in your body longer (fat-soluble vitamins A, D, E, and K) while others leave through urine (water-soluble vitamins like C and the B vitamins). This section builds on that foundation, highlighting nutrients that support bone health, energy, digestion, and healing. Whether through food or supplements, understanding what your body needs can help you feel more confident and supported.

Vitamin D: Why It Matters

Many people with breast cancer have low levels of vitamin D, and researchers are still studying why.

What we do know:

Low vitamin D can contribute to bone thinning and osteoporosis.
Some early research suggests a possible link between low vitamin D and breast cancer risk.

What’s recommended?

Current guidelines suggest taking between 400–1,000 IU (International Units) of vitamin D per day. Most multivitamins fall within this range, but talk to your doctor to confirm what’s best for you.

Minerals

Magnesium, Potassium, Iron, and Calcium

Woman in pink athletic wear holding a water bottle, standing in a grassy field with trees in the background.

What Does Magnesium Do?

Magnesium plays a quiet but crucial role in your health—especially during and after cancer treatment. It supports everything from your muscles and bones to your energy levels and immune system. If your magnesium is low, your body will let you know. Here’s what to watch for—and how to get more of this important mineral into your diet.

Magnesium is a mineral found in your bones, muscles, body fluids, and soft tissue (the tissue that surrounds your organs and helps your body function). It helps your body:

Convert carbohydrates, proteins, and fats into energy
Build strong bones and proteins
Keep your immune system working well
Help your muscles contract (including your heart)
Send nerve signals so your body knows what to do

Could You Be Low on Magnesium?

Certain medications or ongoing issues like vomiting or diarrhea can lower your magnesium levels over time. If you’re not getting enough magnesium, your body may start to send signals. Talk to your doctor if you notice any of the following:

Ongoing nausea
Muscle weakness or cramps
Feeling unusually tired or fatigued

Smart Ways to Boost Magnesium

Steam your vegetables instead of boiling them (boiling can reduce magnesium levels)
Snack on dry roasted nuts
Choose whole grain products like whole wheat bread and brown rice
Include at least one cooked green vegetable daily

Try an easy to make, High-Magnesium Drink if solid food is hard to tolerate, here’s a simple, nutrient-rich drink:

Mix 1 cup powdered milk into 1 quart of regular milk to make “enriched milk.”
Add 1 packet of Carnation Breakfast Essentials to 8 ounces of the enriched milk. This gives you approximately 135 mg of magnesium.

Person with curly hair relaxing on an orange sofa, head tilted back against a white wall, wearing a casual gray top.

Potassium

Potassium is an essential mineral that helps your muscles, nerves, and heart work properly.

Cancer treatments, certain related conditions, or some medications can lower your potassium levels—sometimes without warning.

A simple blood test can check your levels. If potassium is too low, you might feel unusually tired, weak, or get muscle cramps. More serious symptoms include dizziness, fainting, or changes in your heartbeat. If that happens, contact your cancer care team immediately.

If Your Potassium Level is Low

Medical Guidance

Follow your care team’s guidance to temporarily increase your intake of potassium-rich foods

Potassium Intake

Aim to consume more than 2,000 milligrams of potassium per day, unless advised otherwise by your doctor

Food Options

Choose potassium-rich options like bananas, potatoes, spinach, and other nutrient-dense foods

Managing High Potassium: What to Know

If your potassium levels are too high, you may need to make some temporary changes to your eating habits. Treatment, certain medications, or other related health conditions can raise potassium levels in the body. Your care team will let you know if you need to adjust your intake—and for how long.

Why It Matters: Too much potassium in your blood (a condition called hyperkalemia) can cause serious symptoms. Call your care team right away if you experience:

Belly pain or diarrhea
Heart palpitations or chest pain
Weakness or numbness
Nausea

Lowering Potassium in Your Diet

If you’ve been told to limit potassium, your care team may recommend:

Consuming less than 2,000 mg of potassium per day
Tracking your daily intake from food and drinks
Temporarily avoiding or limiting high-potassium foods

Smart Tips to Reduce Potassium

Read food labels. Always check serving size and potassium content per portion.
Watch portion sizes. Even low-potassium foods can add up if you eat large portions.
Drain and rinse canned fruits, vegetables, and meats to remove extra potassium.
Soak vegetables in water before cooking to lower their potassium content.

Person in a wheelchair working at a desk, using a printer, with another person at a table in the background.

Boost Iron, Support Energy

When you’re dealing with anemia or low energy, getting enough iron can make a meaningful difference. Iron helps your body produce healthy red blood cells, which are essential for carrying oxygen and keeping your energy up—especially during or after cancer treatment.

Try adding more of these iron-rich foods to your meals and snacks:

Lean meats like fish and poultry
Eggs
Beans and lentils
Dark leafy greens like spinach or kale (Note: Combining leafy greens with citrus such as a squeeze of lemon or orange slices can help your body absorb it better.)
Beets
Dried fruits (like apricots, prunes, or raisins)

If you’re concerned you might not be getting enough iron, talk with your care team. They can help you decide whether dietary changes—or supplements—make sense for you.

Calcium: Don’t Overlook It

Calcium works with vitamin D to keep bones strong. It’s especially important after menopause when bone loss risk increases.

Before menopause: Aim for 1,000 mg per day
After menopause: Increase to 1,500 mg per day
Best source: Food, not supplements (unless directed by your doctor)

What Are Supplements?

A supplement is anything you eat or drink to add nutrients your body may be missing. They come in many forms: pills, gummies, powders, bars, and drinks. Supplements may contain vitamins, minerals, proteins, or herbs.

Thinking About Taking a Supplement?

Before adding a supplement to your routine, ask yourself:

What benefit am I hoping to get from this?
Is there a specific symptom or concern I’m trying to address?
Have I discussed this with my care team?

What to Look for on a Supplement Label

Name of the supplement
Complete list of ingredients
Third-party tested
Manufacturer name and contact info
Recommended dosage
Country of origin (use caution with imported products)

More Isn’t Always Better

Even if your goal is to be healthy, more isn’t always better—especially with fat-soluble vitamins. For example, too much vitamin D can lead to kidney stones. Water-soluble vitamins are less risky but can still cause discomfort in high doses.

FAQ: Supplements & Safety

Are supplements necessary for everyone?

Should I start several supplements at once?

What if I heard about a supplement from a friend or online?

Can supplements interact with cancer treatment?

Managing Misinformation

Ads and social media often promote supplements with vague or misleading claims. The FDA does not approve or regulate supplements like medications. That means:

Ingredients and dosages may vary
Claims may not be backed by science
“Natural” doesn’t always equal safe. Some supplements may be contaminated or made with impure or lower-quality ingredients.