Foods and Nutrients That Help and Hurt Bone Health
What nutrients do I need, aside from calcium, to keep bones strong?Vitamin D
According to J. Edward Puzas, PhD, a professor of orthopedics at the University of Rochester Medical Center, "The main function of vitamin D is to assist the intestine in calcium absorption. Without it, even though a person consumes calcium, the calcium may not enter the circulation." Other than calcium, experts consider vitamin D3 (cholecalciferol) -- a form of vitamin D that occurs in fish-liver oils -- to be the most important nutrient for bone health.
And although the recommended daily dose is 400 international units, Robert R. Recker, MD, a professor of medicine and director of the Osteoporosis Research Center at the School of Medicine Creighton University, recommends 1,000 international units per day of vitamin D3. Elderly people who do not go outside much and who have little dietary intake of calcium may require as much as 2,000 international units per day in the form of supplements.
There are few natural food sources of vitamin D (e.g., cod liver oil, tuna fish, and salmon); however, the best source is the sun. Exposure to sunlight provides most humans with their vitamin D requirement. You only need about 10 to 15 minutes of sunlight for vitamin D synthesis; after that make sure to put on sunscreen. Keep in mind, sunscreens with a sun protection factor (SPF) of 8 or greater will block UV rays that produce vitamin D.Vitamin K
Some recent studies suggest that the combination of calcium, vitamin D, and K is better for bone health than calcium alone or just calcium plus vitamin D. Vitamin K helps bone hold onto the calcium it has. Research says it creates a biochemical reaction in a bone protein called osteocalcin and helps the protein bind to the calcium and thus build and maintain bone.
Exactly how much vitamin K is needed for this function is still being researched, but the recommended daily allowance (RDA) is 65 micrograms for women and 80 micrograms for men. Luckily, vitamin K can be found in abundance in dark green vegetables, such as spinach and broccoli, and some oils, such as soybean oil. Two servings of broccoli or one serving of spinach provide four to five times what you need in a day.Potassium
Higher potassium intake, primarily from fruits and vegetables, has been associated with higher baseline bone density and less bone loss, says Dorothy Teegarden, PhD, a professor of nutrition at Purdue University. "Potassium influences calcium homeostasis by promoting urinary conservation and lowering excretion of calcium. Thus, low-potassium diets increase urinary calcium losses and high-potassium diets reduce it.
"In addition, increased intake of potassium may decrease the higher bone resorption that can be caused by high-salt diets," she adds. Potassium salts also help neutralize bone-depleting metabolic acids, says Primal Kaur, MD, director of the Osteoporosis Clinic at Temple University School of Medicine in Philadelphia. Teegarden suggests about 4.7 grams per day for adults. Food sources include chicken, turkey, fish, fruits (such as bananas, raisins, and cantaloupe) and vegetables (such as celery, carrots, and potatoes).Magnesium
According to the Surgeon General's Office, 60 percent of the magnesium in our bodies is found in our bones in combination with calcium and phosphorus. Magnesium appears to enhance bone quality. Studies suggest that it may improve bone mineral density, and not getting enough may interfere with our ability to process calcium. The RDA for women is 320mg and for men 420mg. Green vegetables are a good dietary source.
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