Tag Archives: oxalic acid

Bone Up To Avoid Bone Loss

Are your bones rattling for more milk?  If your calcium intake isn’t sufficient, your bones become your body’s backup source of calcium.  Calcium, the most abundant mineral in the body, is needed for nerve conduction, blood vessel contraction and dilation, muscle movement and even cellular communication.  If calcium intake is not sufficient to perform all these activities then the body pulls the calcium from the bones.  Later in life this leads to osteoporosis, a debilitating condition causing vertebrae to crumble, increased likelihood of fractures with falls, and stooped posture.

Bone Formation

Bones are constantly in a state of renewal.  In adolescence, more bone is created than removed, with peak bone mass attained by the early twenties.   Around 30, that ratio reverses to more bone breakdown than creation.  The more bone mass attained in those crucial first two decades, the better the bones can weather the aging process.  Unfortunately,  43% of the US population, even with the use of supplements, fails to get adequate calcium intake – particularly girls ages 4 to 18, and males aged 9-18 and over 51.

Bones Require Adequate Calcium Intake

Getting adequate calcium intake, either through diet or supplements, is essential for bone strength.  And making sure your children and young adults are getting the minimum requirements is really an investment in the future.  The chart below, along with much of the information here is from the NIH, lists recommendations based on age and sex.  Our bodies only absorb about 30% of the total calcium that is consumed.   There are many factors that affect absorption including:

Calcium Recommendations

  1.  The amount consumed at one time.  The more calcium consumed, the less is absorbed.
  2.   Rate of absorption decreases with age, going from 60% as infants to less than 15% in older adulthood.
  3.   Adequate vitamin D intake enhances calcium absorption.  Vitamin D is obtained from sunlight and dietary intake.
  4. Alcohol intake can reduce calcium absorption and also interfere with the production of Vitamin D into its active form.
  5.  Interaction of dietary calcium with other food components, particularly oxalic and phytic acid.  High levels of oxalic acid are found in spinach, collard greens, beans, sweet potatoes and even rhubarb.  High levels of phytic acid are found in whole grains, beans, seeds, nuts and soy isolates.  So consuming milk with any of these foods will decrease the absorption of calcium from the milk.

Factors Affecting Absorbed Calcium

Once calcium is absorbed, there are other factors that can leach calcium out of our bodies through urine, feces and sweat.

  1. High sodium intake increases calcium excretion.
  2. Consuming a diet high in protein and grains increases the production of metabolic acids which then increase calcium excretion.  Eating more fruits and vegetables shifts the body’s acid base balance to a more alkali environment that decreases calcium excretion.

Good Sources of Dietary Calcium

Certain foods are very high in calcium and are easy and affordable to consume.  The chart below lists the best sources of calcium:Foods High In Calcium

Labels do not list the actual amount of calcium in a product, only a percentage based on a 2000 calorie diet.  Making sure people under 30 consume at least 3 servings from the top foods on this list will give huge payback in years to come.  As a child I remember eating sardines crumbled up with saltine crackers.  Sardines are also really high in omega 3’s and an excellent source of protein, I just wish I liked them now.  My primary sources of dietary calcium are yogurt, low-fat milk and occasionally cheese.  I do take a calcium carbonate supplement that provides 333 mg per tablet.

Bone Up On Your Calcium Intake

Pay attention to how much calcium you are consuming.  Getting too much calcium can cause constipation and has also been associated in some studies with prostate cancer and heart disease.  Aim for three servings of the top three listed foods and you know you are getting enough.  Having worked as a nurse in long term care and seeing the frequency of spinal compression fractures and hip fractures, especially in women, motivates me to be mindful of my calcium intake.  Maintain your bone bank by making adequate daily calcium deposits!

Barbara writes a biweekly blog to help inform and empower people to live healthier lives.  Please “share” her articles and “like” her facebook page to help spread the word