Foods for Healthy Bones- Sources and Requirement

Doctor! What are foods for healthy bones? What should I eat so that I get strong bones and joints?

I received this question in my mail recently. Actually, it is an often asked question. Not only this, some people are interested in superfoods for healthy bones.

Well! Before we discuss the foods for healthy bones that make your bones strong, I wish to clarify about superfoods.

There are no superfoods for bone or other health aspects.

It is more of a marketing term to grab your attention.

See, the purpose and function of the food we eat is to provide nutrients. The body utilizes these nutrients to build and repair our body and thwart diseases.

There are five major groups of food

• Proteins
• Carbohydrates
• Fats
• Vitamins
• Minerals

When each of nutrient group is present in our diet in an optimum and recommended amount, the diet is considered a balanced diet.

As a child grows, skeleton accumulates bone mass. The bones remain strong in adulthood and after that, the bone mass starts declining.

Therefore, the requirement of different nutrients varies with age. It could also vary with the type of physical exertion and targets. For example, bodybuilders require more proteins to build strong muscles.

What are the Nutrients Needed for Bone Building and Metabolism?

Read about bone anatomy and physiology

Bones consist of two things- protein matrix and minerals. Calcium forms the main mineral content of the bone. Vitamin D3 plays a role in calcium metabolism. Most of the vitamin D is available naturally and is available to us by virtue of sunlight. Therefore, a healthy dose of sunshine should provide an adequate amount of vitamin D3. A body rich in vitamin D3 would utilize calcium better and thus have stronger bones.

When we advise foods for making your bone healthier, these foods are the ones which are rich in calcium. Here are the foods which are rich in calcium and are good for bone health. Calcium is the cornerstone of strong bones. 

Exercise also has got to play a role in building healthy bones. It has been found that bone mass is more in persons who exercise than who do not.

For supplying enough nutrients, a  healthy diet is essential to build strong bones as the child grows and in adulthood, it maintains the strength.

As we noted before, bone is composed of proteins and various minerals of which calcium is the major mass contributor. Other important minerals are magnesium, silicon,  boron,  copper, and manganese.

Vitamin D is the main vitamin required for extracting calcium from the diet [increases absorption of calcium in the gut] and sending calcium to bone from blood. Therefore, in deficiency of vitamin D, no amount of calcium-rich foods or supplements are going to help.

Vitamin C and K are also involved in bone metabolism.

Adult Dietary Requirements of Foods for Healthy Bones

• Vitamin D – 600-800 IU
• Calcium – 1000-1200 mg
• Phosphorous – 700-4000 mg/day
• Magnesium- 320-420 mg
• Copper-0.9 mg
• Zinc 8-11 mg
• Manganese 1.8-2.3 mg
• Vitamin K – 90-120 µgm
• Vitamin C-75-90 mg

Recommended dietary allowance has not been established for silicon and boron. However, it is thought that silicon 40 mg and boron – 3 mg daily should be good enough for maintaining good bone health.

The requirement is generally more for children and teenagers.

With this background now we would come to different foods that would provide one or more nutrient of bone building.

Food Sources for Various Bone Nutrients

Vitamin D Foods

Vitamin D is normally synthesized in the skin on exposure to sunlight. Therefore, normally it is not required in the diet. But recently, an increased prevalence of vitamin D insufficiency has been reported in children as well as adults. This probably due to reduced exposure to sunlight.

Therefore, one should maintain proper sun exposure which could vary from 10-60 minutes a day several times a week.

The length of exposure would change with a skin complexion as darker people need more exposure than lighter.

Foods that supply vitamin D are

• Fatty fish, like tuna, mackerel, and salmon
• Beef liver
• Cheese
• Egg yolks

Apart from this, fortified foods like

Foods fortified with vitamin D, dairy products, orange juice, soy milk, and cereals etc.

Vitamin D supplements are also available.

Calcium Rich Foods

Milk

The biggest and most easily available calcium source is milk. A single 8-ounce cup of milk has 300 milligrams of calcium.

Yogurt and Cheese

A cup of yogurt has at least as much calcium as an 8-ounce cup of milk. And 1 ounce of Swiss cheese has nearly as much. These options are good for people who have milk intolerance or cannot drink milk for some other reason.

Sardines

Eating 3 ounces of canned sardines delivers a little more calcium than a cup of milk.

Vegetables

Calcium is plentiful in many vegetables. Dark leafy greens such as Chinese cabbage, collard, and turnip greens, offer a lot of calcium.

Soy Food

Half a cup of calcium-enriched tofu contains as much as 861 milligrams of calcium. Isoflavones which have been found to enhance bone density are also found in good quantities soy foods, such as tofu.

Salmon

They contain calcium as well as vitamin D, which assists in calcium absorption. They are also high in omega-3 fatty acids.

Nuts

Walnuts and flaxseeds are packed with omega-3 fatty acids. Peanuts and almonds contain potassium, which protects against the loss of calcium in the urine. Nuts also contain protein and other nutrients that play a supportive role in building strong bones.

Fortified Foods

Fortified foods are products that do not naturally contain calcium but have been enhanced with varying amounts of the essential mineral. Fortified juices and cereals are available and can be a good source of calcium. Check the nutritional label for the exact amount.

Calcium Supplements

Supplements are an easy way to boost your calcium intake, but some reports suggest you may not need them if you’re already getting enough calcium from food.

Dietary Sources of Phosphorous

Calcium combines with phosphates to deposit in the bone. Phosphorous is available in the diet in a number of the foods. Phosphorous deficiency is rare unless there is a metabolic issue.

Recommended allowance is 700mg/day and the maximum allowed limit is 4000 mg/day. Following are few phosphorous-rich foods

• Poultry – chicken, turkey
• Seeds
• Seafood
• Whole grains
• Nuts
• Meat

Magnesium Rich Foods

Magnesium is required in small quantity but is an essential mineral of bone. Following foods are rich sources of magnesium.

• Almonds
• Cashews
• Peanuts
• Raisins
• Bran cereal
• Kidney beans
• Lentils
• Potato skins
• Brown rice,
• Milk

Foods Sources of Silicon

It has been found that dietary more than 40 mg/day of silicon correlates with increased bone mineral density

Silicon is found in whole grains, green beans, cereals like barley and carrots. Some brands of mineral water may have orthosilicic acid. 

Beer is made from cereals and is a good source of silicon. It is thought that this deficiency is less in males due to beer drinking.

Foods that Provide Boron

Though exact mechanism is not clear, boron stabilizes and extends the half-life of vitamin D and estrogen. About 3 mg of boron per day is known to increase bone strength.

Prunes, raisins, dried apricots, or avocados are important sources.

Zinc Foods

Recommended daily allowance of zinc is 11 mg/day in men and for women is 8 mg/day. Often zinc is found in sufficient quantity in a routine diet but vegetarians may have a deficient diet. Main sources of zinc are 

• Red meat
• Poultry
• Shellfish
• Seeds and Nuts
• Beans. 

Manganese Foods

Manganese is also found in sufficient quantities in food.

Recommended Daily Allowance is 1.8 mg/day for women and 2.3 mg/day for men.

Dietary sources of manganese are

• Pineapples
• Mollusks (Clams, Mussels)
• Beans
• Dark Chocolate
• Cinnamon
• Teat
• Nuts
• Cereals, nuts, pineapples, beans, mollusks (clams, oysters, mussels), dark chocolate, cinnamon, and tea.

Copper Dietary Source

Copper is recommended in a quantity of 0.9 mg/day. Copper too is widely available in foods including meats, nuts, grains, seafood, and cocoa. 

Vitamin K and Vit C Sources

Vitamin K is recommended in quantity 90 micrograms (women) and 120 micrograms (men).

Vitamin K is required for carboxylation of osteocalcin, a bone protein and its deficiency leads to osteopenia and increased fracture risk.

Mai dietary sources are

• Collard greens
• Spinach (fresh)
• Kale,
• Brussels sprouts
• Iceberg lettuce
• Prunes 

Vitamin C

Since its discovery as the nutrient whose deficiency led to scurvy, vitamin C has revealed many roles it plays in the body and now is one of the foods for healthy bones.

Vitamin C has been found essential for the formation of collagen and for fracture healing.

Also increased bone mineral density has been noted in postmenopausal women taking vitamin C supplements.

Vitamin C is recommended in the dosage of 75-90 mg per day. Citric fruits (orange, kiwi, lemon, guava, grapefruit), are the most important sources. Other sources are broccoli, cauliflower, Brussel sprouts, and capsicums.

Should Supplements Be used?

Use of supplements is based upon eating habits of the population. American data shows that there is a need for supplementation of Vit D, calcium, magnesium, silicon, vitamin K, and boron.

Supplements of the nutrients which are present adequately in the diet are not required. For example, phosphorous, copper and manganese and zinc.

However, the choice can be made on an individual basis.

References

• Heany R. The vitamin D requirement in health and disease. J Steroid Biochem Mol Biol. 2005;97:13–9.
• Vormann J. Magnesium nutrition and metabolism. Mol Aspects Med. 2003;24(1-3 ):27–37. 
• Jugdaohsingh R. Silicon and bone health. J Nutr Health Aging. 2007;11:99–110. 
• Bügel S. Vitamin K and bone health in adult humans. In: Litwack G, editor. Vitamins and Hormones: Vitamin K. London: Elsevier; 2008. pp. 393–416.
• Newnham R. Essentiality of boron for healthy bones and joints. Environ Health Perspect. 1994;102S(S7 ):83–95S. 
• Hall S, Greendale GA. The relation of dietary vitamin C intake to bone mineral density results from the PEPI study. Calcif Tissue Int. 1998;63(3 ):183–9. 
• Maret W, Sandstead HH. Zinc requirements and the risks and benefits of zinc supplementation. J Trace Elem Med Biol. 2006;20:3–18.