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Calcium Citrate and Vitamin D: The Facts Explained by Experts

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    Calcium citrate with vitamin D is a common supplement combination, designed to support bone health. Read on to learn more.

    Calcium citrate with vitamin D is a popular supplement combination that boasts a number of health benefits. The supplements themselves come in a variety of forms, possessing different amounts of calcium and vitamin D. In this article, we’ll explore everything you need to know.

    What is calcium citrate?

    Calcium citrate is one of the two main forms of oral calcium supplementation, with the other being calcium carbonate. Studies have shown that calcium citrate has a higher bioavailability than calcium carbonate, which means it’s more easily absorbed by the body.

    Calcium is the most abundant mineral in the body. It’s essential for blood clotting, muscle formation, and enzyme and hormone function. It’s also important for helping your body maintain healthy blood pressure already within normal limits and a healthy heart rate. What calcium is probably most known for, though, is its support of bone health. It also works synergistically with vitamin D.

    The recommended daily allowance (RDA) of calcium is 1000 mg to 1200 mg. Some food sources of calcium include yogurt, fortified orange juice, cheeses, broccoli, seeds, fish (sardines/salmon), and legumes. It’s important to know, too, that alcohol and smoking can deplete calcium levels.

    What is vitamin D?

    Vitamin D is a fat-soluble vitamin that’s naturally found in many foods and is available as a supplement. There are two types of vitamin D: D2 (ergocalciferol) and D3 (cholecalciferol). Vitamin D2 is synthesized by plants and not produced by our bodies. Our bodies create vitamin D3 when our skin is exposed to sunlight. However, many of us don’t get enough direct light to meet our vitamin D requirements. Getting some sun exposure – without sunblock – between the hours of 10 a.m. and 4 p.m. may support vitamin D synthesis. Still, other factors affect our body’s ability to synthesize vitamin D3, including the aging process and skin pigmentation.

    Vitamin D is essential for immune health and bone health. It supports bone health in the way it promotes effective calcium absorption in the gut. Furthermore, it helps support bone growth. Without sufficient vitamin D, your bones may weaken. Taking calcium and vitamin D together can help promote bone health, even among older adults.

    Vitamin D promotes calcium absorption in the gut and maintains adequate serum calcium and phosphate concentrations to enable normal bone mineralization and regulate contraction of muscles. Lack of or excess calcium can contribute to issues such as cramps and spasms. It is also needed for bone growth and bone remodeling by osteoblasts and osteoclasts. Without sufficient vitamin D, bone issues can develop. Vitamin D sufficiency promotes bone health in children and in adults. Together with calcium, vitamin D also helps protect older adults from potential bone issues.

    For adults over the age of 19, the recommended daily allowance of vitamin D is 15 mcg or 600 IU.

    What is calcium citrate with vitamin D?

    Calcium citrate with vitamin D is a supplement that combines the mineral and the vitamin. It’s a popular supplement because of the synergistic relationship between vitamin D and calcium. Vitamin D helps regulate bone health and metabolism and helps transport calcium through the intestinal wall.

    Benefits of calcium citrate with vitamin D

    This combination supplement can be used to address low blood calcium levels and to support general bone health. Moreover, it can be used to support healthy smooth muscle movement in the blood vessels through contraction and expansion.

    Calcium citrate with vitamin D is also sometimes used simply to make sure certain people get enough calcium; such people include those who are pregnant, nursing, or postmenopausal, as well as people taking certain medications. This study found that dietary supplementation with calcium and vitamin D improved bone strength and increased bone mineral density in people over 65 years of age.

    How to use calcium citrate with vitamin D

    First, you should talk to your doctor about whether calcium citrate with vitamin D is right for you. If you decide that it is, seek out a supplement from a trusted source. Follow the directions on the package. If your daily recommended dose is more than 600 mg, divide it up over the course of the day.

    You can take this combination supplement in liquid, capsule, or chewable form. If you choose the liquid form, be sure to measure the dose accurately. If you choose the chewable form, chew thoroughly. If you choose capsules – the most common form – swallow them whole. You may or may not want to take your supplement with food. This is a question for your pharmacist or doctor.

    To make sure this or any other supplement works properly, consistency is the key. Work it into your existing supplement routine to make sure you don’t miss any doses. If this supplement is part of a particular diet, be sure to follow the diet with consistency, too.

    Potential side effects and interactions

    Before taking a calcium citrate with vitamin D supplement, be sure to talk to your doctor or pharmacist about any other medications you may be taking. In some cases, this supplement can have negative interactions with certain medications.

    Some potential side effects include gastrointestinal problems such as nausea and vomiting. Excess vitamin D can lead to a host of complications, including nausea, vomiting, dehydration, fatigue, and more. With that said, vitamin D toxicity is exceedingly rare. Talk to your doctor about checking your vitamin D levels.

    Excess calcium, too, can lead to some problems, including fatigue, constipation, weight loss, and more. Again, it’s important to talk to your doctor before proceeding with any supplement, including a calcium supplement.

    Final takeaways

    Calcium and vitamin D work together synergistically to support bone health. Calcium citrate with vitamin D is a popular combined supplement that can help improve your calcium absorption and bone health. You should talk to a doctor before adding such a supplement to your routine.

    You might want to try Care/of’s Calcium Plus supplement, which includes vitamin D and vitamin K2 to improve absorption. Again, consult with a doctor or pharmacist before deciding on a new supplement.

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    Dr. Carla Montrond Correia ND, CNS
    Medical Content Manager
    Dr. Montrond-Correia is a licensed naturopathic physician and a certified nutrition specialist (CNS). She holds degrees from University of Bridgeport, Georgetown University, and University of Saint Joseph, and supplemented her education with internships in the health and wellness space. She's focused on research, herbal medicine, nutrigenomics, and integrative and functional medicine. She makes time for exercise, artistic activities, and enjoying delicious food.
    Our Editorial Staff
    Freelance Contributor
    The Care/of Editorial Team is made up of writers, experts, and health enthusiasts, all dedicated to giving you the information you need today. Our team is here to answer your biggest wellness questions, read the studies for you, and introduce you to your new favorite product, staying up to date on the latest research, trends, and science. Each article is written by one of our experts, reviewed both for editorial standards by an editor and medical standards by one of our naturopathic doctors, and updated regularly as new information becomes available.