Vitamin D for Osteoporosis

Medically Reviewed by Poonam Sachdev on August 31, 2023
7 min read

Planning to eat right for healthier bones? Calcium is probably the nutrient you think of first. But vitamin D is just as important for keeping bones strong and preventing osteoporosis, a disease that can make bones weak and brittle.

Vitamin D helps your intestines absorb calcium from the food you eat. Getting enough of both nutrients can help keep your bones dense and strong.




Unlike calcium, which you only get through food, your body makes vitamin D when sunlight touches your skin. Active people who live in sunny regions can get at least some of the vitamin D they need from spending time outdoors every day. But in less temperate areas like Minnesota, Michigan, and New York, the skin makes less vitamin D in the winter months, especially if you're older.

The amount of vitamin D your skin makes depends on where you live, how light or dark your skin is, and the time of day you’re outside. It could be about 15 minutes for a very fair-skinned person and an hour or two for someone with darker skin. But be careful – too much time in the sun raises your chance of getting skin cancer. Even though sunlight is a key part of your body’s vitamin D production, it’s best to protect your skin with clothing and sunscreen if you’ll be outside for more than a few minutes.

How else can you get vitamin D? A few foods have it, such as:

  • Fatty fish, like salmon, tuna, and mackerel
  • Beef liver, cheese, and egg yolks
  • Foods with added vitamin D, such as milk, orange juice, and cereal

But it’s hard to get the amount you need from food alone. Experts recommend 600 international units (IU) of vitamin D per day for adults up to age 70, and 800 IU for people 71 and older. If you’re not getting enough from sunlight and food, you may need to take a supplement.

Multivitamins can be a source of vitamin D. You can take this supplement with a calcium supplement or on its own. Keep in mind, though, that many diet supplements have vitamin D. So before you take another one, check the labels and let your doctor know what you’re taking. Getting too much vitamin D, especially above 4,000 IU per day, can be dangerous.

If you already have osteoporosis, keep in mind that vitamin D and calcium alone are not enough to treat the disease. You’ll need to take them along with other medications your doctor prescribes.

Some foods can disrupt your body's ability to store or absorb calcium and vitamin D, which can contribute to osteoporosis as you age.  

Osteoporosis diet danger 1: salt is bad for the bone!

Salt can pose a major obstacle to a sturdy skeleton. The more salt we consume, the more calcium we lose through our pee. If you eat too much salt, you may lose enough calcium that your bones could weaken over time. 

Because the average Western diet is high in salt and low in fruits and vegetables, the calcium requirements for Americans are high to maintain balance in the body. The 2020 Dietary Guidelines for Americans advise limiting sodium to 2,300 milligrams a day – equal to a teaspoon of salt. But most Americans get at least 3,400 milligrams of sodium a day. For every 2,300 milligrams of sodium you take in, you'll lose about 40 milligrams of calcium in your urine.

Research has found that postmenopausal women who eat a high-salt diet lose more bone minerals than other women of the same age.

Getting the recommended amounts of calcium and vitamin D every day helps offset bone loss from salt.

  • Adults up to age 50 require 1,000 milligrams of calcium daily – a little more than about three 8-ounce glasses of milk.
  • Older adults need 1,200 milligrams of daily calcium – about three and a half 8-ounce glasses of milk.

Of all the dangers to your bone health, salt might be the hardest to curb. Salt shows up in nearly all processed foods. Choose no-added-salt versions whenever possible, and cut back on high-salt foods like:

  • Processed meats, such as deli turkey and ham, and hot dogs
  • Fast food, such as pizza, burgers, tacos, and fries
  • Processed foods, including regular and reduced-calorie frozen meals
  • Regular canned soups and vegetables and vegetable juices
  • Baked products, including breads and breakfast cereals

Osteoporosis diet danger 2: some popular drinks

Many soft drinks and other carbonated drinks contain phosphoric acid, which can increase the amount of calcium you lose in your pee. And nearly all soft drinks lack calcium. That combination spells trouble for those at risk of osteoporosis.

In general, nutritionists recommend balancing your phosphorus and calcium intake. If your body's levels of dietary phosphorus are higher than its levels of calcium, your body will draw calcium from your bones to try to balance itself.

To help prevent osteoporosis, instead sip these drinks:

  • 8 ounces of orange juice fortified with calcium and vitamin D
  • A mixture of fortified orange juice and seltzer or club soda that's free of phosphoric acid
  • A smoothie, made with 8 ounces of fat-free yogurt, one medium banana or a cup of fresh or frozen berries, and two ice cubes, prepared in a blender or food processor 
  • Fat-free plain or chocolate milk

Osteoporosis diet danger 3: the cost of caffeine

Caffeine leaches calcium from bones, sapping their strength. For every cup of coffee you drink, you may lose about 4 milligrams of calcium.

That's not as much of a loss as from salt, but it's still worrisome. Caffeine is a particular problem for those who don’t get enough calcium each day to begin with.

The good news is that adding a 1-2 tablespoons of milk to your coffee probably offsets any calcium losses that caffeine causes.

Coffee is a major caffeine source. For example, a 16-ounce cup of coffee can provide 192 milligrams of caffeine. High-caffeine sodas can contain up to 33 milligrams per can or more.

Although tea also contains caffeine, studies suggest it doesn't harm, and probably helps, bone density in older women, regardless of whether they add milk to the beverage. Researchers think that tea has plant compounds that help protect your bones.

Ready to curb your caffeine intake? Here are some tips:

  • Wean yourself from coffee by drinking half-regular and half-decaf drinks to start.
  • Avoid caffeine-laden drinks.
  • Reach for decaffeinated iced tea or hot tea.
  • Splurge on a decaf, fat-free latte for the extra calcium.

Osteoporosis diet danger 4: is protein problematic?

The idea that protein, particularly animal protein, is problematic for bones is a myth. Bones are about 50% protein. Bone repair requires a steady stream of dietary amino acids, the building blocks of body proteins. Getting enough protein every day can help prevent osteoporosis.

The suggested daily protein intake is 0.8 grams of protein per 2.2 pounds for men and women over age 19. That amounts to about 55 grams of protein a day for a 150-pound woman and about 64 grams a day for a 175-pound man.

Get the protein you need to bolster bones with these protein sources:

  • 3.5 ounces light tuna, drained: 19 grams protein
  • 3 ounces cooked chicken, turkey, or pork tenderloin: about 20 grams
  • 3.5 ounces cooked salmon: 25.5 grams
  • 8 ounces fat-free plain yogurt: 10 grams
  • 8 ounces fat-free milk: 8 grams
  • 1 medium egg: 5.5 grams

Osteoporosis diet danger 5: there's something about soy

While soy products such as edamame, tofu, tempeh, and soy beverages are rich in bone-building protein, they contain plant compounds that may hamper calcium absorption.

Oxalates in soy can bind up calcium and make it unavailable to the body. Problems may arise when you eat a lot of soy but don’t eat a lot of calcium.

The research is mixed about soy. Some small studies show soy can cause problems with bone strength; others show that the right type of soy (with the soy isoflavones genistein and daidzein) protect bone strength. To avoid any risk, be sure to get a lot of calcium in your diet, mostly through dairy foods or supplements.

Soy products fortified with calcium may not provide as much of the mineral as you think. Researchers who studied calcium-added beverages found that much of the calcium in soy and other beverages sank to the bottom of the container and couldn't be mixed back into the drink, even with shaking.

Still, fortified soy products, such as tofu made with calcium, provide a hefty dose of bone-building nutrients. If your diet is heavy on soy, be sure to also take in at least 1,000 milligrams of calcium every day.