Your body needs vitamin D to absorb calcium. Calcium keeps your bones and muscles—including your heart—healthy and strong.
People who do not get enough calcium and vitamin D throughout life have an increased chance of having thin and brittle bones (osteoporosis) in their later years. Thin and brittle bones break easily and can lead to serious injuries. This is why it is important for you to get enough calcium and vitamin D as a child and as an adult. It helps keep your bones strong as you get older and protects against possible breaks.
Your body also uses vitamin D to help your muscles absorb calcium and work well. If your muscles don't get enough calcium, then they can cramp, hurt, or feel weak. You may have long-term (chronic) muscle aches and pains. Getting enough vitamin D helps prevent these problems.
Children who don't get enough vitamin D may not grow as much as others their age. They also have a chance of getting a rare disease called rickets, which causes weak bones.
Calcium should always be taken along with vitamin D, because the body needs vitamin D in order to absorb calcium.
Recommended calcium intake (milligrams a day)
Recommended vitamin D intake (international units a day)
Males 51-70 years
Females 51-70 years
71 and older
Women who are pregnant or breastfeeding need the same amount of calcium and vitamin D as other women their age.
Most people get enough calcium, but some people may not get enough vitamin D. Many foods are fortified with calcium and vitamin D, and your body uses sunshine to make its own vitamin D. From age 9 through 18, girls need more calcium from foods to meet the daily recommended intake. If they cannot get enough calcium from foods, a calcium supplement may be needed.
Blood tests for vitamin D can check your vitamin D level. But there is no standard normal range used by all laboratories. You're likely getting enough vitamin D if your levels are in the range of 20 to 50 ng/mL.
Things that reduce how much vitamin D your body makes include:
Calcium is in foods such as milk, cheese, and yogurt. Vegetables like broccoli, kale, and Chinese cabbage have calcium. You can get calcium if you eat the soft edible bones in canned sardines and canned salmon. Foods with added (fortified) calcium include some cereals, juices, soy drinks, and tofu. The food label will show how much calcium was added.
Vitamin D is in foods such as salmon, tuna, and mackerel. These are some of the best foods to eat when you are trying to get more vitamin D. Other foods that have vitamin D, but in small amounts, include cheese, egg yolks, and beef liver. You can also get vitamin D from fortified foods such as milk and some cereals, orange juices, yogurts, margarines, and soy drinks.
Some people who do not get enough calcium and vitamin D may need supplements. Calcium supplements are available as citrate or carbonate. Calcium carbonate is best absorbed when it is taken with food. Calcium citrate can be absorbed well with or without food. Spreading calcium out over the course of the day can reduce stomach upset and helps your body absorb the calcium better. Try not to take more than 500 milligrams (mg) of calcium supplement at a time.
Vitamin D supplements are available as ergocalciferol (D2) and cholecalciferol (D3).
It is possible to get too much calcium and vitamin D. Older women who take calcium supplements need to be careful that they do not take too much.
The amount of calcium and vitamin D you get every day from all sources—including food, sunshine, and supplements—should not be more than the amount shown by age in the table below for "upper level intake." Upper level intake does not mean that most people need this amount or should try to get it. It means this is the maximum amount of calcium or vitamin D that is safe to take.
Upper level calcium intake (milligrams a day)
Upper level vitamin D intake (international units a day)
51 and older
If you get too much calcium, you may get kidney stones, and if you get too much vitamin D, your kidneys and tissues may be damaged.footnote 3 Too much calcium can cause constipation. Too much vitamin D can cause nausea and vomiting, constipation, and weakness.
Getting too much vitamin D increases the amount of calcium in your blood. If this happens, you can become confused and have an irregular heart rhythm.
Calcium and vitamin D may interact with other medicines. A drug interaction happens when a medicine you take changes how another medicine works. One medicine may make another one less effective, or the combination of the medicines may cause a side effect you don't expect. Some drug interactions are dangerous.
Before you start taking calcium and/or vitamin D, tell your doctor about all of the medicines you take, including over-the-counter drugs, herbs, and pills. Also tell your doctor about all of your current medical problems.
Food and Nutrition Board, Institute of Medicine (2011). Dietary reference intakes (DRIs): Recommended dietary allowances and adequate intakes, elements. Available online: http://iom.edu/Activities/Nutrition/SummaryDRIs/~/media/Files/Activity%20Files/Nutrition/DRIs/New%20Material/2_%20RDA%20and%20AI%20Values_Vitamin%20and%20Elements.pdf.
Food and Nutrition Board, Institute of Medicine (2011). Dietary reference intakes (DRIs): Recommended dietary allowances and adequate intakes, vitamins. Available online: http://iom.edu/Activities/Nutrition/SummaryDRIs/~/media/Files/Activity%20Files/Nutrition/DRIs/New%20Material/2_%20RDA%20and%20AI%20Values_Vitamin%20and%20Elements.pdf.
Institute of Medicine (2011). Dietary Reference Intakes for Adequacy: Calcium and Vitamin D, pp. 345–402. Washington, DC: National Academies Press. Available online: http://books.nap.edu/openbook.php?record_id=13050.
Current as of:
September 8, 2021
Author: Healthwise StaffMedical Review: Kathleen Romito MD - Family MedicineRhonda O'Brien MS, RD, CDE - Certified Diabetes Educator
Current as of: September 8, 2021
Author: Healthwise Staff
Medical Review:Kathleen Romito MD - Family Medicine & Rhonda O'Brien MS, RD, CDE - Certified Diabetes Educator
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