Vitamin D and calcium are two essential nutrients that can have a big impact on health. Although both are known for their respective health benefits, did you know that they actually work together in the body? It’s true — getting enough of each is equally important when it comes to bone health, weight control, cancer prevention and more. Meanwhile a calcium or vitamin D deficiency can have long-lasting effects on overall health.

So how does vitamin D affect calcium levels? How much calcium and vitamin D do I need? And can I take vitamin D without calcium? Here’s what you need to know.

How Do Vitamin D and Calcium Work Together?

Calcium and vitamin D are two important micronutrients that work together in the body to support overall health. The complex vitamin D and calcium relationship is especially crucial when it comes to bone metabolism, as both are integral to maintaining the strength of the skeleton.

Calcium serves as the key structural component of the bones, and an estimated 99 percent of the body’s calcium is stored in the bones alone. A lack of calcium can cause serious side effects, including bone loss and osteopenia, a condition that is characterized by a weakening of the bones in the body.

However, getting enough calcium through diet or supplementation isn’t always enough to protect against bone loss. In fact, having low vitamin D and high calcium levels can still lead to osteopenia and osteoporosis. This is because vitamin D helps facilitate the absorption of calcium, allowing the body to use it more effectively.

Including an array of foods high in calcium and vitamin D in your diet and selecting a high-quality supplement can optimize vitamin D and calcium absorption. Plus, taking the two together can maximize the potential health benefits of these power-packed micronutrients.

Health Benefits of Vitamin D and Calcium

1. Strengthen Bones

Improved bone health is one of the biggest benefits of calcium and vitamin D. In fact, bone loss is one of the most notable vitamin D and calcium deficiency symptoms, which could potentially lead to issues like osteoporosis, a condition that increases the risk of fractures by causing bones to become weak and brittle. According to one study out of Ireland, calcium is necessary for supporting the health and structure of the bones, while vitamin D helps boost calcium absorption, promotes calcium balance in the body and maintains skeletal integrity.

2. Support Healthy Pregnancy

Both vitamin D and calcium are absolutely essential for ensuring a healthy pregnancy and fostering fetal growth and development. One large trial out of South Carolina found that taking 4,000 international units of vitamin D per day was safe and effective for pregnant women, noting that a deficiency could cause serious issues like neonatal seizures and adverse effects on pregnancy. Similarly, another review reported that calcium supplementation during pregnancy could reduce the risk of pre-eclampsia by 52 percent and may also be linked to a lower risk of pre-term birth, plus a higher birthweight.

3. Promote Weight Loss

If you’re having difficulty shedding stubborn body fat, you may want to consider adding vitamin D and calcium supplementation to your routine, especially if you think that you may be deficient in one of these key micronutrients. Interestingly enough, studies show that eating less calcium or having lower blood levels of vitamin D may be linked to a higher body weight. One study published in Nutrition Journal even found that taking calcium and vitamin D together for 12 weeks led to significant decreases in body fat compared to a placebo.

4. Could Help Protect Against Cancer

Promising research shows that both calcium and vitamin D could have a major impact on cancer development. For example, a large review in the American Journal of Public Health found that getting adequate amounts of vitamin D could be associated with a lower risk of colon, breast, prostate and ovarian cancers. Other studies show that consuming more calcium may also be linked to a lower risk of colorectal and breast cancer. More research is needed to determine whether calcium and vitamin D are responsible for these effects or whether other factors may also be involved.

5. Enhance Heart Health

Some studies suggest that taking a vitamin D and calcium supplement could be a quick and convenient way to help keep your heart healthy and strong. In fact, low levels of vitamin D have been associated with an increased risk of heart disease, high blood pressure and heart failure. What’s more, calcium has been shown to reduce diastolic blood pressure, which is one of the major risk factors for heart disease.

How to Get the Right Amount

Figuring out the right calcium with vitamin D3 dosage can get pretty tricky, especially since the guidelines can vary based on a number of different factors. The calcium and vitamin D recommendations for osteoporosis, for instance, may differ from the recommendations for pregnancy or weight loss, and your specific needs can vary based on your age and health status.

Generally, most adults need between 1,000–1,200 milligrams per day of calcium. This can come from calcium foods, calcium supplements or a combination of both. Meanwhile, adults typically need about 600 IU of vitamin D per day, which increases to 800 IU per day after the age of 70. However, many recommend taking a higher dosage calcium and vitamin D supplement, especially if you’re at a higher risk for deficiency. In some cases, vitamin D doses can range up to 5,000 IU per day. Be sure to use supplements only as directed, and talk to your doctor if you suspect that you may have a deficiency to find the right dosage for you.

Besides determining your dosage, finding the best calcium and vitamin D supplement to fit your needs can also be tricky. Select vitamin D3 over vitamin D2 whenever possible, and be sure to take supplements with food to help maximize absorption. Additionally, opt for calcium citrate instead of calcium carbonate, which can minimize potential side effects and ensure you get the most from your calcium tablets.

Ideally, you should also consume a good variety of calcium and vitamin D foods to help meet your daily needs for these two important nutrients. Some of the top foods rich in calcium and vitamin D include cheese, fortified milk and certain types of fish. In addition to consuming foods with calcium and vitamin D, getting regular sun exposure a few times per week can also help you meet your vitamin D needs.

Risks and Side Effects

Vitamin D and calcium are incredibly important. Symptoms of low calcium and vitamin D can range from bone loss to muscle pain to cramps and weakness. If you think that you may have deficiency, your doctor can test your blood levels to help determine the best course of treatment for you.

Keep in mind that there are several calcium and vitamin D side effects that you should be aware of if you do decide to start supplementation. A few of the most common symptoms include nausea, vomiting, constipation and fatigue. In some studies, calcium supplements have also been linked to a higher risk of kidney stones, prostate cancer and even heart disease, although research has turned up conflicting findings. More studies are needed to understand whether other factors may be involved as well.

Consuming high amounts of either micronutrient can also have harmful side effects on health. Therefore, it’s important to use supplements only as directed and be sure to talk to a trusted health care professional before starting supplementation, especially if you have any underlying health issues or are taking other medications.