Alarmingly High Levels of Lead in Calcium Supplements: Pb Content per Serving Up to 18x Over "Acceptable Levels".

Image 1: You better pick the right source of calcium: healthy milk / dairy vs. lead poisoned pills from your local pharmacy or supermarket - you still have the choice.

This, I can assure you, is a "SuppVersity News", i.e. something you will not read on the major news portals, simply because there is too much money at stake in the 3billion $ market for calcium supplements (figure according to January 2008 edition of "Heartwire") - money a huge part of which is spent by Novartis & Co to advertise their products to consumers from all age groups, regardless of the individuals' dietary calcium intake; and that despite accumulating evidence for an association of supplemental calcium intake and heart disease (for one of the latest reviews cf. Bolland. 2011)! A very recent study published in the Journal of Biological Trace Element Research (Rehman. 2011) does yet cast another, even darker shadow onto the "healthy" white chalk tabs...

What? "Pb" is not the symbol for Calcium in the Periodic Table?

Lead, that stuff nuclear physicists value, because it effectively absorbs radioactive radiation, is one of the most toxic "heavy metals" we are exposed to. And this is by no way a recent discovery. Even in ancient times, people knew about the toxic effect vessels made of this metal had on the water they contained. Back in 1990 E.K. Silberberg summarized the contemporary knowledge about the dangers of environmental lead exposure in a paper for the Environmental Defense Fund as follows (Silberberg. 1990):

[...] epidemiological studies have suggested that central nervous system (CNS) effects in children are observed at the lowest increments of lead exposure [...] Similarly, clinical studies indicate that early exposure to lead produces functionally irreversible damage to the CNS; experimental research demonstrates that this irreversibility may involve failure to remove lead from brain, permanent effects on synaptogenesis; and chelant-induced redistribution of lead from the periphery to the CNS. [...] New data on release of bone stores of lead during physiological conditions of demineralization indicate that mobilization of bone lead adds to in utero exposure of the fetus. Furthermore, postmenopausal demineralization of bone can increase blood lead levels in women by 25%; this raises concern about the potential effects of lead in an aging population and the difficulties in comprehensive exposure assessment.

As you may have guessed, time has not affected the dangers or the irreversibility of lead toxicity, so that you would assume that the results of an investigation into the lead content of 27 "commonly used" commercially available calcium supplements should be alarming enough to receive at least some public recognition. After all, it would suffice to read the abstract to be alarmed by the fact that of the calcium supplements Sohaila Rehman and her colleagues from the Pakistan Institute of Nuclear Science Technology analyzed only one out of ten "met the criteria of acceptable Pb levels (1.5µg/daily dose) in supplements / consumer products set by the United States" (Rehman. 2011).

Figure 1: Lead levels in µg in daily dose of respective calcium supplement; solid red line = acceptable Pb level for calcium supplements, dashed red line = tolerable total daily Pb intake for children <7y, dotted red line = tolerable daily Pb intake for women in childbearing age (data adapted from Rehman. 2011).

"One out of ten", well that does not sound so bad, does it? I guess you will change your mind, when you take a closer look at figure 1 - the red line at the bottom of the graph is the "acceptable Pb level" and as you can see it is met by exactly 1 out of 13 calcium chelate products (CAC 1000 by Novartis), and none of the 3 calcium chelates the researchers tested for their lead content.

Figure 2: Lead levels in µg in daily dose of respective calcium supplement; solid red line = acceptable Pb level for calcium supplements, dashed red line = tolerable total daily Pb intake for children <7y (data adapted from Rehman. 2011).

And while the lead levels of the calcium + vitamin C and calcium + vitamin D levels in figure 2 look somewhat better, there are still several outliers with Cal-C Plus from Himont Pharma, for example, providing more than 2x the tolerable daily lead intake for a child under the age 7 y (and remember these are only the official FDA figures - and you know what that means ;-) on a per serving base.

Note: The results of the study at hand may well explain a) the different outcomes of (controlled) trials and epidemiological studies on the effects of calcium supplements on cardiovascular health and b) the beneficial effects of milk and dairy intake on heart health (Soedamah-Mutuh. 2011). After all, a very recent study that was published in the Journal of Neurotoxicology and Teratology in October 2011, shows that there is a "potential for autonomic dysregulation" that manifests in "significantly greater vascular resistance and reduced stroke volume and cardiac output" in 9-11 year old children even "at levels of Pb typical for many US children" (the exact levels were 1.01µg/dL, cf. Gump. 2011).

And as if all that was not enough, the US Food and Drug Administration (FDA) and the glorious Center for Disease Control and Prevention (CDC) would have been aware of the potential of serious chronic lead intoxication from calcium supplements, if they spent more time reading scientific journals than counting the cashflow from the BigPharma companies that finance their bureaucracy. After all, Bourgoin et al. conducted a very similar study back in the 1990s, the results of which the scientists summarize in their abstract as follows (Bourgoin. 1993):

Daily lead ingestion rates revealed that about 25% of the products exceeded the US Food and Drug Administration's "provisional" total tolerable daily intake of lead for children aged 6 years and under.

In the Rehmann study it were 16 out of 27 tested calcium supplements (59%) which exceeded this limit. So  maybe the "feds" just did not act, because 1 out of 4 is not bad enough? Well, if you look at the individual results in figure 3 (usually I redo graphs, but in this case the original looks just too damn impressive), it is immediately obvious that the averages the scientist report in their abstract, do not reflect the actual potential of lead toxicity from the 70 supplemental sources Bourgoin et al. tested.

Figure 3: Results of a 1993 large-scale analysis of the lead content of 70! commercially available calcium supplements and milk (my emphasis), the safe exception (from Bourgoin. 1993)

Obviously, some of the bone based and a whole host of the "natural sources" ("natural source of calcium carbonate" according to label claim; note that coral calcium would fall into this category, as well!) are about as toxic as the worst offenders in the Rehman study. What I find do yet find particularly interesting, is that the lead content in one serving of commercial milk, which would provide the same amount of (even more bioavailable) calcium as the supplements in the study did, would provide no more than 0.71µg/day and is thusly the one and only "natural source" of dietary calcium that does not set you up for lead toxicity!

"Pah, lead!? What doesn't  kill you just makes you stronger"

Image 2: So, calcium supplement with lead are a safe source of dietary calcium, but raw milk is not? (img CounterThink)

In view of the "longstanding" history of ignorance on behalf of the governmental agencies, it sounds almost sarcastic, when Bourgoin et al. conclude their article by citing the Center for Disease Control's (CDC) statement on lead poisoning, which according to these reputable protectors of the health of the American society *cough* is "one of the most common and preventable pediatric health problems today". Notwithstanding this early insight (this is from a 1991 document from the CDC) the officials obviously have neither taken Bourgoin et al.'s advice to control calcium supplements "more rigidly" in order to "prevent unnecessary exposure in all segments of the population, particularly young children" (Bourgoin. 1993), nor have they followed the recommendation of a more recent study by Kim et al., which  estimates the mean lead intake from calcium supplements to about 5µg/day and recommends that "measures to prevent potentials of Pb toxicity from overtaking some Ca supplements should be considered" (Kim. 2010).

And while the CDC and the FDA could incidentally have missed those papers. They should actually be aware of Proposition 65, which is the common name for California's Safe Drinking Water and Toxic Enforcement Act of 1986 (Dietary Supplement Standard 173, Metal Contaminant Acceptance Levels. NSF International. August 19, 2003). In this paper, of which W.W. Kilgore writes in retrospective that (Kilgore. 1990)

[i]t creates a list of chemicals (including a number of agricultural chemicals) known to cause cancer or reproductive toxicity; [i]t limits discharges of listed chemicals to drinking water sources; [i]t requires prior warning before exposure to listed chemicals by anyone in the course of doing business; [i]t creates a list of chemicals requiring testing for carcinogenicity or reproductive toxicity; and [i]t requires the Governor to consult with qualified experts (a 12-member "Scientific Advisory Panel" was appointed) as necessary to carry out his duties.

the proposed Acceptable Intake Level (AIL) for inorganic lead (as extrapolated from animal studies) is 0.5µg/day and thusly 1/3 of the current Californian standards and 1/50 of the FDA allowance of 25µg/day! But hey, who cares? As long as the American citizens are protected from the dangers of raw milk, everything is all right, isn't it?

Overweight or Just "Heavy Bones"? Recent Studies Provide Insights Into How Your Bones Affect Your Metabolism

Image 1: The yellow bone marrrow fat
turns out to be more than a filler.

In Germany there is a common saying that is predominantly used by the mothers of fat kids: "My son, overweight? No. He just has some really heavy bones." Well, I guess few of these proud mothers will be aware that recent research from the Boston Medical School (Fulzele. 2011) and the University of Toledo suggests that there may be more to the bone-bodyweight connection than even they may have thought.

In a comprehensive review of the latest findings on bone metabolism (Fulzele. 2011) Keertik Fulzele and Thomas L. Clemens state that the "contemporary model [which] assigns IGFs [insulin like growth factor] as central regulators of cell profileration, survival, and organism growth" and reduces the influence of insulin to the "level of regulation fuel utilization, storage, and energy expenditure" is too simplistic to to accommodate the overlapping roles of IGF and insulin in several physiologic processes, one of which is the recently discovered and previously unappreciated skeletal action of insulin. Via skeletal insulin receptors, the latter is intricately involved in

• osteablast [=bone cells] bone acquisition
• osteocalcin production

Of these, the production of the noncollagenous peptide ostecalcin could be of special interest with respect to the metabolic function of bone, as its undercarboxylated form (carboxylation of osteocalcin occurs in the presence of vitamin K and "activates" the peptide hormone, so that it can fulfill its bone-building function), which has a low affinity for bone matrix, appears to function as a hormone on the systemic level. On the other hand, insulin has lately been found to increase the accumulation of undercarboxylated osteocalcin, which "in turn acts in an endocrine fashion to regulate pancreatic insulin secretion and peripheral insulin responsiveness". It is this hitherto unknown mechanism by which your bones factor in the complex hormonal game that is your metabolism and by which skeletal energy-sensing pathways may manage fuel production, storage, and expenditure in a similar vein as their analogues in muscle and fat tissue.

Figure 1: Metabolic and endocrine functions of white (WAT) and brown (BAT) adipocytes in your bone marrow
(based on Czernik. 2011)

As the scientists point out, we are just beginning to understand the sophisticated role our bones play in the orchestration of our metabolism. Questions that still have to be answered relate to the ways, osteablasts "sense" glucose and other fuels, whether they simply burn amino acids and glucose as fuel and whether and to which extent medications that influence bone resorption could also be used for blood sugar management.

Answers to these questions will expand our understanding of the biology of the skeleton and should have implications in the diagnosis and management of patients with metabolic diseases, including osteoporosis and diabetes.

More information on the underlying mechanisms by which your bones directly influence your metabolic rate, and thus your weight, can be found in a Special Issue of the Journal 'Bone', entitled "Bone and Fat". In her paper (Czernik. 2011), Beata Lecka-Czernik elaborates on the possible influence the yellow bone fat, which - believe it or not - occupies a significant portion of your bone marrow cavity, could have on your metabolism, both locally, as well as systemically.

Did you know? The fat distribution in your skeleton is site, age, and gender specific (men have more bone fat than women). In adults the bone marrow cavity of long bone, for example, is entirely filled with fat, while the ileac crest marrow contains only ~40% fat. The overall amount of bone fat can double in the course of your life and the WAT- and BAT-like adipocytes appear to have similar metabolic and endocrine functions as their white (WAT) and brown (BAT) analogues on your hips, your belly and your neck.

In this context, the integrative models of Ferron et al and Fulzele et al. are of particular interest, as they could help elucidate the link between the anabolic effects of insulin signaling in osteoblasts and the regulation of insulin sensitivity in peripheral organs. And who knows, even if its not the "heavy bones" that contribute to the obesity pandemic,"fat bones" could well become a novel target in its prevention and treatment.

Exhaustive Aerobic Exercise Increases Serum Calcium Levels and Dietary Requirements

You probably have heard of the fundamental importance of calcium as a structural component of bones. Yet, calcium is way more than the building block of our bone structure and the concrete the of the hopefully non-existent plaque in your arteries. It is also one of the major players in muscle contraction. Thus, it is not very surprising that a group of Iranian Scientists (Pourvaghar. 2011) found major effects of pro-longed (15min) high intensity aerobic exercise on serum calcium levels of 12 randomly selected student athletes (22.36y; 75kg @ 1.76m):

[…] the participants' mean of serum calcium concentration in the first stage and before Balke exhausting aerobic exercise was measured 98.38 ng/mic L. In the second stage, i.e. after the exhausting aerobic activity, it increased to 114.96 ng/mic L. Research results indicated that the difference in serum calcium concentration between the first and second stages is significant (P= 0.0001).

With the calcium that is appearing in the blood of the athletes being leeched from bones, organs to fulfill the increased calcium needs of active muscle tissue. Due to calcium “consumption” and urinary losses, the scientists speculate, the overall result to be a negative calcium balance.

Figure 1: Serum Calcium levels of athletes before, immediately after and 24h after exhaustive aerobic exercise. (Pourvaghar. 2011)

In view of the fact that, in the 24h after exercise, there is no sudden falloff (only -9.13%) of blood calcium, I would yet advice against extensive calcium supplementation. Previous works from other researchers have conclusively shown that a nutritionally dense, calorically adequate, diverse, calcium-rich diet satisfies the needs of both, the average gymrat and the hard training endurance athletes.

For athletes on a weight-reduction diet, or active gym-goers who – due to whatever other reasons – consume a diet that is low (<1.000mg/d) in calcium supplementing with a bio-available form of calcium, like calcium citrate, could yet be a viable strategy to prevent bone loss and sustain exercise performance.

Vitamin K for Healthy Bones & a Lean Physique: Rat Study Finds Phylloquinone (K1) & Menaquinone (K2) Ward off Fat Gain and Cut Triglycerides by Half

Until not too long ago, scientists thought vitamin D was all about bone. Every follower of this blog knows that this is a way too narrow perspective on what turned out to be more of a hormone than a vitamin. A recent study (Sogabe. 2011) on the effects of vitamin K supplementation in mice does now suggest that vitamin D's "cofactors" phylloquinone (PK, vitamin K1) and menaquinone-4 (MK-4, vitamin K2) have been similarly mistaken.

Figure 1: Weight of visceral fat pad in g after 85 days of  phylloquinone (PK, vitamin K1) or menaquinone-4 (MK-4, vitamin K2) supplementation (Sogabe. 2011)

Japanese scientists, who wanted to investigate the effect of 85 days of vitamin K supplementation (PK: 600 mg/kg; MK-4: 600 mg/kg) on bone development in mice, were surprised to find that vitamin K did not only improve bone mass and structure, but that...

the addition of PK or MK-4 significantly decreased the total fat accumulation (p < 0.01 and p < 0.05, respectively), and serum triglycerides were reduced by 48% in the PK group and 29% in the MK group compared with the control.

This is an interesting result, which is not related to increases in growth hormone release, as one might expect in view of the bone-building effects of vitamin K. The scientists speculate: "The effect of vitamin K on fat mass could be mediated through adiponectin regulation which itself has been found to be associated with fat mass." This, as well as the dose response relationship (the human equivalence dose for the amount of PK and MK-4 used in the study would be about 7.5g!) warrant further investigation - and, as always, the SuppVersity is the place to read about it, first!

High Protein Diet Safe for Bones! Acid Load due to Meat Protein does not Compromise Calcium Metabolism.

Reading the caption of this post, some of you may rightly ask themselves: "Why does he even mention this? Of course, meat is safe - meat is natural and eating meat is what man is made for!" So, if you already knew all that, you can stop reading now. If, however, you still belong to the misguided brotherhood of the followers of the holy food pyramid with your "healthy" grains, pasta and cereals at the bottom, you may be interested in the results from an older scientific paper I just came across while posting an answer to a forum post of someone who was concerned that his bones will become brittle if he increases his protein intake beyond the 0.8g/kg body weight barrier.

In November 2010, Cao & Nilsen (Cao. 2010) published a review which analyzed the outcome of studies that investigated the effect of the purported renal acid load resulting from a high protein intake (above the current Recommended Dietary Allowance of 0.8 g protein/kg body weight) on increased urinary calcium excretion. With reference to more recent findings they write:

Neither whole body calcium balance is, nor are bone status indicators, negatively affected by the increased acid load. Contrary to the supposed detrimental effect of protein, the majority of epidemiological studies have shown that long-term high-protein intake increases bone mineral density and reduces bone fracture incidence. The beneficial effects of protein such as increasing intestinal calcium absorption and circulating IGF-I whereas lowering serum parathyroid hormone sufficiently offset any negative effects of the acid load of protein on bone health.

By the way, I am already looking forward to the huge steaks I am going to have for lunch, today ;-)