Calcium and Vitamin D

What is calcium and what does it do?

• Calcium is a mineral found in many foods. It is used by the body to build bones and keep bones and teeth strong. Calcium has other roles in the body too: it helps muscles to contract (tighten), helps nerves to carry messages, cells to give off hormones and blood vessels to move blood.
• About 99% of the body’s total calcium is stored in the bones and teeth.
• Calcium blood levels are carefully controlled by a hormone called parathyroid hormone. This hormone helps control calcium levels by impacting absorption from the intestines, kidneys and bone so the muscles, nerves and blood vessels can use it.

What causes abnormal calcium levels?

Abnormal calcium levels may be caused by unusual parathyroid hormone levels, high or low vitamin D, kidney disease, medicines, severe illness, other hormone abnormalities or bone problems. Your doctor may need to do blood testing to find the cause.

What are the signs and symptoms of low calcium levels?

• People with long-standing low calcium levels may have bone pain or be prone to fractures, although some may have no signs of illness.
• Rapid lowering of calcium or very low calcium levels can cause numbness of the fingertips and mouth, muscle cramps, emotional problems, low blood pressure, seizures and heart problems.

What are the signs and symptoms of high calcium levels?

• Nausea and vomiting
• Loss of appetite
• Constipation (trouble pooping)
• Gut pain
• Muscle and joint pain
• Confusion, dementia (severe confusion and loss of thinking ability)
• Being tired all the time (fatigue)
• Excessive thirst
• Excessive urination (peeing)

How much calcium do people need?

Which foods are good sources of calcium?

• Dairy products such as milk, yogurt and cheese are the best food sources of calcium.
• Green vegetables, nuts, breads, cereals and fortified juices also have good amounts of calcium.

What is vitamin D and what does it do?

• Vitamin D is a fat-soluble vitamin that helps the gut take in (absorb) calcium from food.
• Your skin is able to make vitamin D when you are in direct sunlight. However, being in sunlight too much for too long raises your risk of skin cancer, so prolonged sun exposure is not suggested as a way to prevent or treat a lack of vitamin D.
• Vitamin D can be found in some foods and supplements.
• Both calcium and vitamin D are needed for strong bones: low vitamin D levels are linked to low calcium levels, osteoporosis or osteopenia (low bone thickness) and rickets (softening of the bones in childhood).

Who is at risk for vitamin D deficiency?

• Breastfed infants
• People with dark skin
• People who do not get regular direct sun exposure
• People with liver diseases, kidney disease or malabsorption (the gut can’t take in vitamins, minerals, etc. from food)
• People with obesity
• People on special diets such as vegan or macrobiotic diets
• Elderly people

What are signs of low vitamin D?

• Vitamin D insufficiency and deficiency may have no symptoms.
• If the low level of vitamin D is severe or lasts for a long time you may experience bone and muscle pain, muscle weakness, fractures and/or falls.

How much vitamin D do I need?

• The right amount of vitamin D depends on diet, sun exposure, skin color and underlying medical problems. In general, the recommended amounts range from:
  • 400 IU a day in babies
  • 600 IU a day in people 1 to 70 years of age
  • 800 IU a day in those over 70 years of age
• Vitamin D insufficiency and deficiency will require higher doses of vitamin D supplements to replace the vitamin D stored in the body.

What are food sources of vitamin D?

• Fatty fish
• Cod liver oil
• Eggs
• Mushrooms
• Fortified cow’s milk
• Fortified cereal and bread

Helpful resources

• The National Institutes of Health Osteoporosis and Related Bone Disease National Resource Center provides educational provides patients, health professionals, health educators and the public with an important link to resources and information on metabolic bone diseases including osteoporosis, Paget’s disease of bone and osteogenesis imperfecta.
• American Bone Health teaches people how to build and keep strong and healthy bones for life with practical and up-to-date information and resources to engage, educate and empower them to prevent bone loss, osteoporosis and fractures.
• OrthoInfo is the patient education website of the American Academy of Orthopaedic Surgeons (AAOS).