Should You Take Calcium and Vitamin D Together?

Person taking a pill with a glass of water.

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More than half of people in the United States take a dietary supplement, and calcium and vitamin D are among the most common. Taking calcium and vitamin D together is generally safe under the guidance of a healthcare provider.

Research has been mixed about whether you can take them both at the same time. Taking supplements may raise the risk of getting too much of either nutrient. Too much calcium or vitamin D can lead to heart and kidney problems.

Gender Disclaimer

Health recognizes that not everyone who is a woman was born with female reproductive organs and that not everyone who is a man was born with male reproductive organs. Health also recognizes that people may not identify as any one sex or gender. The information in this article is based on how researchers present their results, and the gender- and sex-based language used most accurately reflects their research design and outcomes.

What the Research Says

One study found that taking calcium and vitamin D supplements together might increase your risk of stroke. The authors looked at previously published evidence concerning how supplements affect human health. Many of the studies that have looked at the use of calcium and vitamin D supplements also rely on follow-up data that lacks precision.

Other studies have found that using calcium and vitamin D supplements is safe in moderation, particularly for older adults. Research has shown that the use of both supplements is still not overly helpful.

Why You Need Calcium

About 98% of your body's calcium supply can be found in your bones. Having enough calcium is important for:

  • Blood clotting
  • Blood vessel contraction and dilation
  • Bone health
  • Hormonal secretion
  • Muscle function
  • Nerve communication

How Much You Need

Adults need the following daily amounts of calcium:

  • Men aged 19-70 years old: 1,000 milligrams (mg)
  • Men aged 71 years and older: 1,200 mg
  • Women aged 19-50 years old: 1,000 mg
  • Women aged 51 years and older: 1,200 mg
  • Pregnant people: 1,000 mg
  • Breastfeeding people: 1,000 mg

Why You Need Vitamin D

Vitamin D also protects your bones and supports your muscles. It's also necessary to help with:

  • Calcium absorption
  • Immune system functioning
  • Nerve communication

One of the most popular ways to get vitamin D is going outside. Your body makes and stores vitamin D when sunlight reaches your skin.

How Much You Need

Adults need the following daily amounts of vitamin D:

  • Adults aged 19-70 years old: 15 micrograms (mcg)
  • Adults aged 71 years and older: 20 mcg
  • Pregnant people: 15 mcg
  • Breastfeeding people: 15 mcg

Risks and Side Effects

It's good to have adequate amounts of calcium and vitamin D to help your body function. Both supplements can have drug interactions. It's also possible to have too much of these nutrients from taking supplements.

Potential Drug Interactions

Both supplements can interact with certain medications. Calcium supplements might have interactions with:

  • Dolutegravir, which is an HIV medicine
  • Levothyroxine, or a thyroid hormone
  • Lithium, which treats bipolar disorder
  • Quinolone antibiotics

Vitamin D supplements can have interactions with:

  • Cholesterol-lowering statins
  • Orlistat, or a weight loss drug
  • Steroids
  • Thiazide diuretics, which treat hypertension (high blood pressure)

Risks

You may have high levels of calcium, but it's usually the result of a condition rather than supplements. The risks of high calcium intake are:

  • Arrhythmia, or an abnormal heart rhythm
  • Heart disease-related death
  • Nephrolithiasis (kidney stones)

Very high levels of vitamin D in the body usually come from taking too many supplements. Risks may include:

  • Arrhythmia
  • Death
  • Kidney failure

Side Effects

Calcium and vitamin D supplements do not come without potential side effects. You may collectively experience these side effects:

  • Appetite and weight loss
  • Confusion
  • Constipation
  • Dehydration or excessive thirst and urination
  • Low levels of phosphate
  • Muscle weakness or poor muscle tone
  • Nausea or vomiting
  • Pain
  • Poor kidney function
  • Tiredness

How To Take Calcium and Vitamin D Supplements

The Food and Drug Administration (FDA) minimally regulates dietary supplements, which may or may not be suitable for you. Speak with a healthcare provider or pharmacist before you start any supplements.

Dosage

The safest amount of calcium from your diet and supplements is 2,500 milligrams daily. Your body can best absorb calcium at 500 milligrams or less daily. You may spread calcium supplementation throughout the day.

The upper limit for vitamin D is 100 micrograms daily from your diet and supplements. Ensure supplementation alone does not reach this limit unless you have been diagnosed with vitamin D deficiency.

Consult a healthcare provider to determine if you need to take both calcium and vitamin D together. Vitamin D may be available in some calcium supplements.

Timing

When you need to take calcium supplements depends on the type. Take calcium carbonate supplements when you are eating a meal. You can take calcium citrate supplements with or without food.

Vitamin D is fat-soluble, so it can break down in fat. Take it when eating meals with fat content to best absorb vitamin D in its supplement form.

Food Sources of Calcium and Vitamin D

Do not stop taking calcium and vitamin D supplements together if a healthcare provider has instructed it. You may consider making dietary changes where possible if you are worried about your calcium and vitamin D intake and do not take supplements.

Calcium

Many dairy products have calcium, including cheese, milk, and yogurt. Other foods you could eat include:

Vitamin D

Vitamin D is naturally available in limited food sources. Try some of these nutrient-rich options:

  • Braised beef liver
  • Egg yolks
  • Fatty fish like mackerel, salmon, trout, and tuna
  • Fish liver oils
  • Mushrooms
  • Vitamin D-fortified products, such as cereals, milk, and plant-based milk

A Quick Review

Research has been mixed about whether calcium and vitamin D supplements can be taken together. It's generally safe to take at the same time with direction from a healthcare provider. Using calcium and vitamin D supplements may come with risks. You can reduce side effects by taking them properly or increasing your dietary intake of both nutrients.

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9 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Dietary supplement use among adults: United States, 2017–2018.

  2. Kamiński M, Kręgielska-Narożna M, Bogdański P. Determination of the popularity of dietary supplements using Google search rankingsNutrients. 2020;12(4):908. doi:10.3390/nu12040908

  3. Zarzour F, Didi A, Almohaya M, Kendler D. Cardiovascular impact of calcium and vitamin D supplements: A narrative reviewEndocrinol Metab (Seoul). 2023;38(1):56-68. doi:10.3803/EnM.2022.1644

  4. National Institutes of Health: Office of Dietary Supplements. Calcium - fact sheet for consumers.

  5. National Institutes of Health: Office of Dietary Supplements. Vitamin D - fact sheet for consumers.

  6. Khan SU, Khan MU, Riaz H, et al. Effects of nutritional supplements and dietary interventions on cardiovascular outcomes: An umbrella review and evidence mapAnn Intern Med. 2019;171(3):190-198. doi:10.7326/M19-0341

  7. National Institutes of Health: Office of Dietary Supplements. Calcium - health professional fact sheet.

  8. National Institutes of Health: Office of Dietary Supplements. Vitamin D - health professional fact sheet.

  9. MedlinePlus. Calcium supplements.

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