Keeping Your Bones Healthy with These Key Nutrients

While muscles and skin tend to get the limelight when it comes to fitness and wellness, we often forget how essential healthy bone mass is for maintaining our independence and level of activity as we age.

And while it doesn’t get the press like some other diseases, osteoporosis affects nearly 10 million Americans, with 44 million having low bone mass, putting them at increased risk of developing osteoporosis. Furthermore, one in two women and one in four men over the age of 50 will have a bone fracture due to osteoporosis.

While the prevalence of osteoporosis is high, there are ways to reduce our risk through diet. So keep reading to find out more about key nutrients for keeping our bones healthy.

What is Osteoporosis?

Literally translated to “porous bone,” osteoporosis is a bone thinning disease that can result in fractures. While it may sound like something you don’t have to worry about until much later down the road, your lifestyle choices throughout your life can greatly affect your risk of developing osteoporosis as you age.

From childhood through early adulthood is when our peak bone mass is largely determined. During these years, our bodies are able to form new bone faster than old bone is broken down.

While genetics play a large role in what our peak bone mass will be, other lifestyle factors, especially diet and physical activity, greatly affect how much we’re able to increase this peak bone mass.

Between 25-30 years old is when most of us reach our peak bone mass. And this level stays relatively stable until our 40’s and 50’s, when our bodies start to break down old bone faster than new bone is being formed.

While everyone will experience loss of bone mass, certain lifestyle factors can increase or decrease the rate of loss – which we’ll get to later in this post.

But why is osteoporosis so serious? As mentioned above, osteoporosis is a disease that thins and weakens our bones. As a result, even the slightest bump or fall can result in a bone break, usually in the spine, wrist, or hip.

Besides being costly, bone fractures can also lead to permanent reductions in mobility and independence. And even more serious, 20% of elderly individuals that suffer a hip fracture die within one year from complications related to the fracture itself or from repairment surgery.

So, while breaking a bone when you’re younger might sound like more of an inconvenience than a danger, osteoporotic bone fractures are very serious and even life-threatening. But the good news? There are steps we can take to keep our bones healthier for longer. Today, we’re going to focus on ways to adjust your diet to promote bone health.  

Key Nutrients for Bone Health

While there are many nutrients that play a role in developing and maintaining healthy bones, we’ll focus on five of the biggies.

Before we get going, please note that before taking any supplements, make sure to talk with a doctor or dietitian to make sure they won’t interact with any current medications as well as find the safest dose for your individual needs.

Calcium

Role in Bone Health

While we normally think of bones as being purely structural, they’re also the primary storage site of calcium in the body. Calcium is an essential nutrient, meaning that our bodies can’t make it on its own and instead it must be consumed through the diet.

While our bones need calcium in order to build and maintain bone, calcium is also essential for muscle contractions (including contractions of the heart muscle), nerve transmission, intracellular signaling, and hormone secretion. As a result, when there is inadequate calcium in the diet, our bodies have to pull from the reservoir of calcium in the bone to meet these other physiological demands.

RDA

The recommended intake for calcium varies by age, with children and adolescents aged 9-18 needing the most calcium. 1300 mg/day, as that’s when bone growth is the most rapid.

For adults aged 19-50 years, the RDA is 1,000 mg/day. This amount stays the same for males until their 70’s, when needs are increased to 1,200 mg/day.

For women, calcium needs increase to 1,200 mg/day starting at age 51 and continue throughout adulthood.

Food Sources

While not exhaustive, here are a few good sources of calcium (and not all of them are dairy):

• ½ cup firm tofu = 861 mg

• 1 ounce parmesan cheese – 331 mg

• 7 sardines = 321 mg

• 1 cup fat-free milk = 306 mg

• 6-ounces plain yogurt = ~300 mg

• 1 cup low-fat milk = 290 mg

• 1 cup whole milk = 276 mg

• 3-oz canned salmon = 232 mg

• 6-ounces Greek yogurt = 150-200 mg

• 1 cup canned white beans = 191 mg

• 8 dried figs = 107 mg

• 1 cup cooked edamame = 98 mg

• ¼ cup almonds = 72 mg
• 1 cup soy milk = 61 mg

As mentioned above, there are many other sources of calcium as well, including seeds, lentils, oranges, fortified orange juice, and fortified oats and breakfast cereals.

Leafy greens can also be a good source of calcium (especially kale and collard greens). However, some greens, such as spinach, are also high in oxalates, which bind to calcium and make it harder for your body to absorb it.

Supplements

There’s limited evidence that calcium supplements are effective in preventing osteoporosis or fracture risk in older adults living at home (1, 2). 

Furthermore, there are some concerns of side effects with calcium supplements, including GI-related effects, kidney stones, and possibly heart issues. Talk with a doctor before taking calcium supplements. 

Vitamin D

Role in Bone Health

Vitamin D plays a large role in bone health through multiple mechanisms, including promoting calcium absorption, promoting mineralization of bone by helping to maintain serum calcium and phosphorus levels, and plays a role in the process of bone remodeling.

Research has shown that inadequate vitamin D intake over long periods of time can lead to bone demineralization. Additionally, it’s long been known that vitamin D deficiency can lead to rickets in children and osteomalacia in adults, diseases in which the bone softens and can lead to deformed bones.

RDA

While our bodies do synthesize some vitamin D from sunlight exposure, how much vitamin D you actually obtain varies greatly on weight, age, skin color, geographical location, and time of year.

The Institute of Medicine currently recommends 600 IU of vitamin D per day for individuals aged 1-70, 800 IU for adults older than 70, and 400 IU for infants 0-12 months.

Currently, it’s recommended that individuals avoid taking more than 4,000 IUs per day unless instructed by a medical professional.

Food Sources

While sunlight is the primary source of vitamin D, there are a few natural and fortified food sources of vitamin D:

• 1 tablespoon cod liver oil = 1,360 IU

• 3-ounces cooked salmon = 446 IU

• 3-ounces canned tuna = 154 IU

• 1 cup fortified orange juice = 137 IU

• 1 cup milk = 115-124 IU

• 2 sardines = 46 IU
• 1 large egg (with the yolk) = 41 IU

Supplements

Due to the limited amount of vitamin D in food sources and the importance of wearing sunscreen, vitamin D supplements are often a good option for most people.  

When buying supplements, always go with a reputable brand and look for Vitamin D3, as it’s more potent than D2. A daily dose of 1000-4000 IU is generally sufficient for most people, but it’s always a good idea to talk with a medical professional for more personalized recommendations.

Magnesium

Role in Bone Health

Approximately 60% of the magnesium in the body is stored in bone, with the rest being found in muscle, soft tissue, and fluids. While magnesium is required for over 600 biochemical reactions in the body, it also plays an important role in bone growth and maintenance of serum calcium levels. Some research has suggested that it may also help prevent against bone fractures; however, the research is still mixed.

RDA

Current recommendations are 400 mg for males aged 19-30, and then 420 mg for males 31 and over.

For women, the recommendations are slightly less: 310 mg for those aged 19-30, and 230 for those 31 and over.

Note: during pregnancy and lactation these needs increase. For pregnant women aged 19-30, 350 mg are recommended during pregnancy and 310 mg during lactation. For women 31 and over, needs increase to 360 mg during pregnancy and 320 mg during lactation.

Food Sources

Magnesium can be found in a large variety of plant and animal sources. Some good sources include:

• 1 ounce of cashews or almonds = 74-80 mg

• ½ cup cooked spinach = 78 mg

• 1 cup soy milk = 61 mg

• ½ cup black beans = 60 mg

• 2 tablespoons peanut butter = 49 mg

• 2 slices whole wheat bread = 46 mg

• 1 cup cubed avocado = 77 mg
• 3-ounces cooked halibut or salmon = 24-26 mg

Whole grains, nuts, whole soy products, yogurt, chicken, beef, broccoli, apples, bananas, and carrots are all also good ways to get more magnesium.

Supplements

Currently, there’s no strong research showing a benefit on bone health of consuming more magnesium than recommended. As magnesium is widely available in the diet, it’s recommended to first increase intake of magnesium-containing foods. However, if your diet is limited, it can be a good idea to discuss supplementation with a medical professional.

Vitamin K

Role in Bone Health

Known for its role in blood clotting, vitamin K has also been shown to play a role in activating proteins required for bone growth and development.

RDA

The recommended intakes of vitamin K vary by gender. For men 19 years and older, the RDA is 120 mcg/day.

For women 19 and over, the RDA is 90 mcg/day, with needs staying the same during pregnancy and lactation.

Food Sources

While many of the best food sources of vitamin K are dark green, leafy vegetables, fermented foods and animal products are also good sources. Here are a few vitamin K containing foods to add to your diet:

• ½ cup cooked kale = 531 mcg

• 1 leaf raw swiss chard = 398 mcg

• 1 ounce natto (fermented soybeans) = 313 mcg

• 1 cup raw spinach = 145 mg

• ½ cup cooked brussels sprouts or broccoli = 109-100 mcg

• 3-ounces cooked chicken or pork chop = 51-59 mcg

• 1 kiwi fruit = 28 mcg

• 1-ounce hard cheese = 25 mcg
• ½ medium avocado = 21 mcg

Supplements

Research on whether or not vitamin K supplementation beyond dietary intake is effective for improving low bone density is ongoing and in need of further randomized controlled trials. While vitamin K deficiency is rare, if you’re concerned that you’re unable to get sufficient vitamin K, it’s worth talking to a registered dietitian about dietary modifications and possible supplementation.

Note: if you take Warfarin (Coumadin), vitamin K supplementation is strongly discouraged as vitamin K can have a serious interaction with this blood thinning medication.

While it was once thought that you need to limit vitamin K when on Warfarin, current recommendations are to consume a consistent amount of vitamin K daily. It’s very important to talk with your doctor before making any sudden changes to your vitamin K intake, as your prescription dose may need to be altered.

Other Nutrients

As mentioned at the beginning of this article, these aren’t the only nutrients that help with building and maintaining strong bones. Zinc, potassium, manganese, vitamin C, boron, and vitamin B12 all play a role, directly or indirectly, in bone health.  

Furthermore, diets high in fruit and vegetables have been associated with higher bone mass density and lower risk of osteoporosis in middle-aged and elderly adults, likely due to their high concentrations of vitamins, minerals, and antioxidants.

Other Lifestyle Factors

Of course, diet is just one piece of the puzzle. Lifestyle factors, such as smoking, alcohol use, and significant, rapid weight loss (often related to an eating disorder) can all lead to an increased rate of bone loss and increased risk of osteoporosis.

Long-term use of certain medications can also negatively affect bone mass, including glucocorticoids (such as prednisone), certain anti-seizure drugs, and excessive use of aluminum-containing antacids. If you are currently taking one of these medications, it’s important to continue your medication as prescribed and ask your doctor about ways to help counteract this potential side effect.

On the other hand, regular physical activity can positively affect bone health and reduce the risk of osteoporosis. Regular weight-bearing exercise (such as walking, hiking, running, dancing, tennis) and strength-training exercises (with free-weights, machines, and/or body weight) throughout life are essential for building and maintaining healthy bones.