Oxalates & Vitamin C

One of the most commonly used vitamin supplements -used in the aid of improving the body’s defense system, improved bone growth and muscle development. This supplement is vital for our general wellbeing. But is there ever a discussion about overdose? Can we ever use too much of this power vitamin? The answer is ‘yes’. After all, too much of a good thing is never good at all.

Discovered by the Hungarian biochemist- Albert Szent-Györgyi, vitamin C (ascorbic acid) was found to possess many health benefits. Among them are;

1. Aid in the formation of collagen, used to make skin, tendons, ligaments, and blood vessels. 2. Heal wounds and form scar tissue. 3. Repair and maintain cartilage, bones, and teeth. 4. Aid in the absorption of iron. Now most would be familiar with the foods rich in vitamin C, which include Citrus, strawberries, broccoli, spinach, tomatoes and red peppers amongst other fruits and vegetables. Many may not be consuming these foods as regularly or may feel the need to have supplemental vitamin C, thus increasing the overall consumption. From the National Institute of Health, the following gives the recommended daily values based on multiple variables.

Table 1: Recommended Dietary Allowances (RDAs) for Vitamin C Age Male Female Pregnancy Lactation 0–6 months 40 mg* 40 mg* 7–12 months 50 mg* 50 mg* 1–3 years 15 mg 15 mg 4–8 years 25 mg 25 mg 9–13 years 45 mg 45 mg 14–18 years 75 mg 65 mg 80 mg 115 mg 19+ years 90 mg 75 mg 85 mg 120 mg Smokers Individuals who smoke require 35 mg/day More vitamin C than nonsmokers. From the above information, it can be seen the average amount of ascorbic needed in one day hardly surpasses 100mg. The body does a great job of excretion but what happens when the rate is elimination is met with a higher rate of ingestion? The result – formation of Oxalates. Oxalates are compounds that are formed in the metabolism of Vitamin C and through the synthesis from other foods we eat. After oxalate is formed, it normally combines with calcium to be excreted in the stool. When large amounts of unabsorbed fat are available (e.g. from fat malabsorption), calcium preferentially binds to fat instead of oxalate. This leaves oxalate available to be easily reabsorbed by the colon and ends up in the urinary tract. In conditions where fat malabsorption is present, oxalate in the urine is elevated. Thus reduced calcium intake will exacerbate the production of Oxalates within the body.

WHAT ARE SOME OF THE SIGNS OF HIGH OXALATE CONCENTRATION?

-Blood in urine -Sharp, severe pain in lower back -Difficulty urinating -“sand” or “gravel”-like stones if the stones are passed out of the body in the urine -If larger stones are trapped in the urinary tract, pain may be present, although some people may have no symptoms.

HOW DO WE MANAGE HIGH OXALATE CONCENTRATION?

Since our bodies produce oxalates naturally from the metabolism of vitamin C, we should consider avoiding Vitamin C overdose. Typically keeping the intake less than or at 500mg.

It is not advisable to reduce the consumption of foods that contain oxalated as most leafy vegetables have oxalate concentration in very small quantities. The key to reduce the formation is by increasing your calcium intake.

For persons with a high genetic disposition of developing oxalate crystals and gout, boiling or steaming vegetables can reduce their oxalate content by 34%. It is quite important to note that gout and hyperoxaluia are sometimes linked so talk to your doctor for more insights.