Getting enough calcium and vitamin D is essential to building strong, dense bones when you're young and to keeping them strong and healthy as you age. The information included here will help you learn all about calcium and vitamin D - the two most important nutrients for bone health.

What is Calcium and What Does it Do?

Calcium is a mineral that is necessary for life. In addition to building bones and keeping them healthy, calcium helps our blood clot, nerves send messages and muscles contract . About 99 percent of the calcium in our bodies is in our bones and teeth. Each day, we lose calcium through our skin, nails, hair, sweat, urine and feces, but our bodies cannot produce new calcium.

That’s why it’s important to try to get calcium from the food we eat. When we don’t get enough calcium for our body’s needs, it is taken from our bones.

Too many Americans fall short of getting the amount of calcium they need every day and that can lead to bone loss, low bone density and even broken bones.

How Much Calcium Do You Need?

The amount of calcium you need every day depends on your age and sex.

*This includes the total amount of calcium you get from food and supplements.

Sources of Calcium

Calcium-Rich Food Sources

Food is the best source of calcium. Dairy products, such as low-fat and non-fat milk, yogurt and cheese are high in calcium. Certain green vegetables and other foods contain calcium in smaller amounts. Some juices, breakfast foods, soymilk, cereals, snacks, breads and bottled water have calcium that has been added. If you drink soymilk or another liquid that is fortified with calcium, be sure to shake the container well as calcium can settle to the bottom.

A simple way to add calcium to many foods is to add a single tablespoon of nonfat powdered milk, which contains about 50 mg of calcium. About two-to-four tablespoons can be added to most recipes.

Reading Food Labels - How Much Calcium am I Getting?

To determine how much calcium is in a particular food, check the nutrition facts panel of the food label for the daily value (DV) of calcium. Food labels list calcium as a percentage of the DV. This amount is based on 1,000 mg of calcium per day. For example:

• 30% DV of calcium equals 300 mg.
• 20% DV of calcium equals 200 mg of calcium.
• 15% DV of calcium equals 150 mg of calcium.

Calcium Supplements

The amount of calcium you need from a supplement depends on the amount of calcium you get from food. Aim to get the recommended daily amount of calcium you need from food first and supplement only if needed to make up for any shortfall. If you get enough calcium from the foods you eat, then you don’t need to take a supplement. I fact, there is  no added benefit to taking more calcium than you need in supplements and doing so may even have some risks.  

 In general, you shouldn’t take supplements that you don’t need. Calcium supplements are available without a prescription in a wide range of preparations (including chewable and liquid) and in different amounts. The best supplement is the one that meets your needs based on convenience, cost and availability. When choosing the best supplement to meet your needs, keep the following in mind:

• Choose brand-name supplements with proven reliability. Look for labels that state “purified” or have the USP (United States Pharmacopeia) symbol. The “USP Verified Mark” on the supplement label means that the USP has tested and found the calcium supplement to meet certain standards for purity and quality.
• Read the product label carefully to determine the amount of elemental calcium, which is the actual amount of calcium in the supplement, as well as how many doses or pills to take. When reading the label, pay close attention to the “amount per serving” and “serving size.”
• Calcium is absorbed best when taken in amounts of 500 – 600 mg or less. This is the case when you eat calcium rich foods or take supplements. Try to get your calcium-rich foods and/or supplements in smaller amounts throughout the day, preferably with a meal. While it's not recommended, taking your calcium all at once is better than not taking it at all.
• Take most calcium supplements with food. Eating food produces stomach acid that helps your body absorb most calcium supplements. The one exception to the rule is calcium citrate, which can absorb well when taken with or without food.
• When starting a new calcium supplement, start with a smaller amount to better tolerate it. When switching supplements, try starting with 200-300 mg every day for a week, and drink an extra 6-8 ounces of water with it. Then gradually add more calcium each week.
• Side effects from calcium supplements, such as gas or constipation may occur. If increasing fluids in your diet does not solve the problem, try another type or brand of calcium. It may require trial and error to find the right supplement for you, but fortunately there are many choices.
• Talk with your healthcare provider or pharmacist about possible interactions between prescription or over-the-counter medications and calcium supplements.

What is Vitamin D and What Does it Do?

Vitamin D plays an important role in protecting your bones and your body requires it to absorb calcium. Children need vitamin D to build strong bones, and adults need it to keep their bones strong and healthy. If you don't get enough vitamin D, you may lose bone, have lower bone density, and you're more likely to break bones as you age.

How Much Vitamin D Do You Need?

 **Some people need more vitamin D. According to the Institute of Medicine (IOM), the safe upper limit of vitamin D is 4,000 IU per day for most adults.

Sources of Vitamin D

There are three ways to get vitamin D:

• Sunlight
• Food
• Supplements

Sunlight

Your skin makes vitamin D from the ultra-violet light (UVB rays) in sunlight. Your body is able to store the vitamin and use it later. The amount of vitamin D your skin makes depends on time of day, season, latitude, skin pigmentation and other factors. Depending on where you live, vitamin D production may decrease or be completely absent during the winter.

Because of concerns about skin cancer, many people stay out of the sun, cover up with clothing and use either sunscreen or sunblock to protect their skin. The use of sunscreen or sunblock is probably the most important factor that limits the ability of the skin to make vitamin D. Even an SPF (sun protection factor) of 8 reduces the production of vitamin D by 95 percent. Because of the cancer risk from the sun, most people need to get vitamin D from other sources, including eating foods rich in vitamin D and taking vitamin D supplements.

Food

Vitamin D is naturally available in only a few foods, including fatty fish like wild-caught mackerel, salmon and tuna. Vitamin D is also added to milk and to some brands of other dairy products, orange juice, soymilk and cereals.

Check the food label to see if vitamin D has been added to a particular product. One eight ounce serving of milk usually has 25% of the daily value (DV) of vitamin D. The DV is based on a total daily intake of 400 IU of vitamin D. So, a serving of milk with 25% of the DV of vitamin D contains 100 IU of the vitamin.

It is very difficult to get all the vitamin D you need from food alone. Most people need to take vitamin D supplements to get enough of the nutrient needed for bone health.

Supplements

If you aren't getting enough vitamin D from sunlight and food, consider taking a supplement. But, before adding a vitamin D supplement, check to see if any of the other supplements, multivitamins or medications you  take contain vitamin D. Many calcium supplements also contain vitamin D.

There are two types of vitamin D supplements. They are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Both types are good for bone health.

Vitamin D supplements can be taken with or without food. While your body needs vitamin D to absorb calcium, you do not need to take vitamin D at the same time as a calcium supplement. If you need help choosing a vitamin D supplement, ask your healthcare provider or pharmacist to recommend one.

How Much Vitamin D Should You Supplement?

To figure out how much vitamin D you need from a supplement, subtract the total amount of vitamin D you get each day from the recommended total daily amount for your age. For example, a 55 year old woman who gets 400 IU of vitamin D from her calcium supplement should take between 400 and 600 additional IU of vitamin D to meet the 800 - 1,000 IU recommended for her age.

Vitamin D Deficiency: Are You at Risk?

Vitamin D deficiency occurs when you are not getting the recommended level of vitamin D over time. Certain people are at higher risk for vitamin D deficiency, including:

• People who spend little time in the sun or those who regularly cover up when outdoors;
• People living in nursing homes or other institutions or who are homebound;
• People with certain medical conditions such as Celiac disease and inflammatory bowel disease;
• People taking medicines that affect vitamin D levels such as certain anti-seizure medicines;
• People with very dark skin;
• Obese or very overweight people; and
• Older adults with certain risk factors.

Talk to your healthcare provider if you meet any of these risk factors or think you might be at risk of vitamin D deficiency. If you have osteoporosis and also have a vitamin D deficiency, your healthcare provider may temporarily prescribe a higher dose of vitamin D.