Calcium is the most abundant mineral in the human body. Almost 99% of the body’s calcium is stored within the bones and teeth. The remaining 1% is found in the blood and soft tissues.
Photo Credit: faria! (Flickr)
Functions
Calcium plays several important roles within the body, including providing structure, cell signaling, serving as a cofactor for enzymes and proteins, blood clotting, and allowing membrane permeability.
Structure
Calcium plays a role in the mineralization of bone. It is a major structural element of both the bones and the teeth. The mineral component of bone consists mainly of hydroxyapatite crystals, which contain large amounts of calcium and phosphate.
Cell signaling
Calcium helps mediate the constriction and relaxation of blood vessels, nerve impulse transmission, muscle contraction, and the secretion of hormones like insulin.
Blood clotting
Calcium ions must be bound in order to activate the seven vitamin K-dependent clotting factors in the coagulation cascade, which stops bleeding through clot formation.
Digestion & Absorption
Calcium is absorbed only in its ionized (Ca2+) form. As a result, it must first be released from the salts in which it is contained (e.g., calcium citrate, calcium carbonate) before it can be absorbed. Under ordinary circumstances, this is accomplished in about one hour at a mildly acidic pH.
There are two main transport processes that are responsible for the absorption of calcium:
1) The first process operates primarily in the duodenum and proximal jejunum. It is saturable and requires energy. This process involves a calcium-binding protein, and it is regulated by calcitriol, the active form of vitamin D. This transport system is stimulated by low-calcium diets and in conditions of growth.
2) The second process occurs throughout the small intestine, but is most prominent in the jejunum and ileum. This process is passive and nonsaturable. Absorption via this mechanism increases when the net calcium intake increases.
Blood Calcium Levels
The level of calcium in your blood is tightly controlled so as to maintain normal physiological functioning. Calcium is so vital to everyday functions that your body will demineralize bone in order to keep blood calcium levels within normal limits.
Calcium, parathyroid hormone (PTH), and vitamin D work together to maintain blood calcium levels. When blood calcium levels begin to drop, the parathyroid glands increase their production of parathyroid hormone (PTH). PTH, in turn, increases the reabsorption of calcium by the kidneys and stimulates the kidneys to convert vitamin D to its active form, calcitriol.
Calcitriol accelerates the absorption of calcium in the small intestine. Working together with PTH, it also stimulates the release of calcium from bone by activating osteoclasts, which are bone resorbing cells. The two also increase the reabsorption of calcium in the kidneys.
Once the blood calcium levels return to normal levels, the parathyroid glands stop secreting PTH, causing the kidneys to return to excreting excess calcium in the urine.
Labwork
Because blood calcium levels are so closely regulated by the body, a blood calcium level is an ineffective marker of calcium status. However, taken together with PTH and vitamin D, you can begin to determine your true calcium status.
An elevated PTH level can indicate that your body is leeching calcium from your bones, especially if paired with a low vitamin D level. This can occur even if your blood calcium levels are normal.
Calcium status is one of the best example of why a basic CBC and CMP are not enough for bariatric patients. While a CMP includes a blood calcium level, your body has mechanisms for protecting the level of calcium circulating in your blood by drawing on its stores—your bones. Only through more extensive testing can you reveal the full picture.
Interactions with Other Nutrients
Vitamin D helps to optimize calcium absorption.
Calcium inhibits the absorption of iron. The effect is stronger with nonheme iron, but also occurs with heme iron, though with higher doses of calcium.
Remember to check the serving size on calcium citrate supplements!
ASMBS Recommendations
Roux-en-Y Gastric Bypass: 1500-2000 mg/day
Duodenal Switch: 1800-2400 mg/day
Adjustable Gastric Band: 1500 mg/day
Vertical Sleeve Gastrectomy: 1500 mg/day
- Choose a brand that contains calcium citrate and vitamin D3. (Calcium carbonate is not well absorbed in individuals with decreased stomach acid. Calcium citrate is absorbed better by everyone, regardless of surgery status.)
- Begin with a chewable or liquid supplement, then progress to a whole tablet or capsule as tolerated.
- Split into 500-600 mg doses. Your body can only absorb 500-600 mg of calcium at a time.
- Be mindful of the serving size on the supplement label. The serving size for calcium is typically two tablets or capsules.
- Space doses evenly throughout the day.
- Do not combine calcium with iron-containing supplements. Calcium inhibits the absorption of iron. Separate calcium and iron-containing supplements by at least two hours.
Sources:
Aills L, Blankenship J, Buffington C, Furtado M, Parrott J. ASMBS allied health nutritional guidelines for the surgical weight loss patient. Surgery for Obesity and Related Diseases 2008;4:S73-S108.
Groff JL, Gropper SS. Advanced Nutrition and Human Metabolism. Belmont: Wadsworth, 2000.
The American Society of Metabolic and Bariatric Surgeons published nutrition recommendations for weight loss surgery patients in 2008. You can download and read the recommendations for yourself here. This document is extremely helpful. It includes information on diet progression, vitamin recommendations, and information on complications and micronutrient deficiencies. I’d highly recommend reading it for yourself.
In the meantime, I’ll include the recommendations for vitamin supplementation. The ASMBS recommendations are a good place to start with supplementation, but know that you may need to alter your vitamin regimen based on your personal labwork.
Continue reading ‘ASMBS Vitamin Recommendations (Reformatted)’
This morning I found myself browsing through back issues of Nutrition when I stumbled upon an interesting study, published in 2008: “Comparison of ferrous sulfate and ferrous glycinate for the treatment of iron deficiency anemia in gastrectomized patients.” Which brings me to one of my favorite topics. Journey Vitamins.
Photo Credit: Journey Vitamins
You’ll remember that Journey uses a special form of iron known as Ferrochel, which is ferrous bisglycinate, an iron glycinate chelate. On its website, Journey makes the following claim:
Clinical studies with Albion’s Ferrochel® have shown Ferrochel® improves hemoglobin and ferritin indices at lower dosages than ferrous sulfate or ferrous ascorbate; lower dosages mean fewer side effects and no interactions with other nutrients.
Well, many members of the community, such as Andrea at WLS Vitagarten, have requested copies of these clinical studies to no avail. The research we do have does not support the use of ferrous bisglycinate, especially not in weight loss surgery patients. This study is no exception.
Continue reading ‘Ferrous Glycinate Chelate and Gastrectomized Patients’
Last week, I attended a local support group meeting for the first time in a few months. Unfortunately, it was an exercise in futility that once again proves that expert advice can be anything but. This surgery is for life. As patients, it is our responsibility to educate ourselves. We have a vested interest in our health that our doctors simply do not share.
Photo Credit: Flickr User SuperFantastic
Continue reading ‘Sleeve Patients Can Stop Vitamins at Two Years Post-Op?!?’
Note: An updated version of this document can be found in PDF form here. Please download and share.
Many years ago, the gold standard for post-operative supplementation was Flintstones children’s chewable vitamins, as well as Tums for calcium. Unfortunately, this regimen was woefully incomplete. Without the proper supplements, people developed deficiencies. Not always immediately—the body has stores of many vitamins—but they did eventually appear. In some people, circumstances helped to accelerate nutrient depletion. My friend Andrea had babies. Greedy little (adorable) things that they were, those babies stole from her vitamin stores. Her Flintstones and Tums simply couldn’t keep up. Andrea got rickets.
These cautionary tales are everywhere in the weight loss surgery world. There are countless post-ops five, ten, or more years out who have dug themselves out from deficiencies that were caused, at least in part, by bad medical advice. Despite these stories and the giant strides that have been made in bariatric and nutritional research, the recommendations given by surgeons are still outdated.
It’s review time here at The Bypassed Life! I’ve had these babies waiting for review for quite a while now. Instead of posting about them, I’ve just been taking them. I guess that’s a review in and of itself…
Celebrate's Chewable Multivitamin in Pineapple Strawberry
Continue reading ‘Review: Celebrate Multivitamin Chewable (Pineapple Strawberry)’
Misinformation makes me angry. Let’s just put that out there. And? There’s a lot of misinformation in the bariatric community. There are a lot of companies looking to make a buck off of bariatric patients. Let’s face it. We’re a pretty willing audience much of the time. Your protein will help us lose weight 10% faster? Awesome! Sign me up! You make sugar-free gummy vitamins that I can take once a day? Send ‘em my way! Utensils that blink when I’m supposed to take a bite? Where do I enter my credit card information?
But there’s a difference between looking to make a profit and actively toying with our health. When you have a prominent role in the bariatric community, you need to hold yourself to a higher standard. When you yourself are a bariatric patient? That standard should be exceptionally high. It’s a matter of personal integrity. Unfortunately, personal integrity appears not to matter to some people.
I’ve already written about Journey Vitamins after trying their product in Houston. I’ve tried to keep my mouth shut on a lot of their faulty advertising for two reasons. First, I really hoped that people were smart enough to see through the bad science on their own. Second, there are others out there pointing out the flaws much better than I ever could. But I’ve reached my breaking point.
Source: Journey Vitamins
Continue reading ‘More Misinformation from Journey Vitamins’
Post-op nutrition and vitamin supplementation is an often-overlooked aspect of bariatric surgery. For patients who have had a Roux-en-Y gastric bypass or a duodenal switch, the bypass of portions of the digestive tract places patients at risk for nutrient malabsorption (1). Moreover, “postoperative deficiencies in protein, iron, and other vitamins and minerals are common and require supplementation to maintain normal levels” (2). Even patients without surgical malabsorption, such as adjustable gastric band or vertical sleeve gastrectomy patients, are potentially at risk for deficiencies, resulting from reduced intake and avoidance of nutrient-dense foods (3).
Unfortunately, many surgeons do not prescribe sufficient supplements and do not order adequate laboratory testing. Andrea Ullberg, of WLS Vitagarten, has created a product to fill that gap. Earlier this month, at the ObesityHelp Houston conference, she debuted the WLS Vitagarten: Lab Tracker Workbook. I have had my book in hand for a few weeks now, and I’d like to share my thoughts with you.
So, at my 18-month lab workup, my iron levels quite frankly stunk. They had been steadily dropping since surgery, despite supplementation.
Welcome to another vitamin post. I’ve previously written a post called “All About Iron.” This is a continuation on that subject. In my “All About Iron” post, I touched on the subject of ferritin and iron storage. This post will go into more depth and explain why ferritin is so important for weight loss surgery patients.
The Ferritin Complex
