Research article

Nutrition to Fight Lead Poisoning

By Robert J. Taylor, additional references sourced by Elizabeth O’Brien, Edited by Anne Roberts,
Photos by Catherine Sweeny. A Fact Sheet version of this Research Article can be found at www.lead.org.au/fs/Fact_sheet-Nutrients_that_reduce_lead_poisoning_June_2010.pdf

Vitamin D (calciferol) has a mixed reputation: it increases the uptake of lead, calcium and iron. In different studies it is associated with both higher and lower lead levels. It may increase blood lead levels when dietary calcium and iron intake is inadequate. It is possible to speculate that good levels of vitamin D may reduce lead deposition in the bones if calcium, magnesium and phosphorus nutrition is adequate, but may release lead from bone if calcium, magnesium and phosphorus intake is inadequate due to increased bone resorption (the recycling of calcium and other minerals including lead from the bone to the bloodstream). Vitamin D is essential to the effective utilization of calcium for bone formation and significant deficiency can negate or even reverse some of the advantages of calcium supplementation. It also increases magnesium and phosphorus absorption but unfortunately calcium competes with phosphorus for absorption. Solid Vitamin D levels may help protect against H. pylori infections that reduce stomach acidity, in turn reducing iron, zinc, copper, calcium and vitamin B12 absorption.

Distortion of the vitamin D metabolism is one effect of lead toxicity, reducing the amount transformed into the form most useful to the human body (1,25-dihydroxycholecalciferol [(1,25(OH)2D)] ), though at moderate lead levels (less than 20 µg/Dl), this appears to have major impacts only when other nutrient intakes, notably calcium, are inadequate. Vitamin D is produced in the body from exposure to sunlight, but individuals who get insufficient sun exposure, always wear sunscreen when outdoors, or are dark skinned and living in temperate/boreal zones may need to obtain significant vitamin D from their diet. In the USA most milk, though not milk products (eg. cheese, yogurt), are fortified with vitamin D, and fortified dairy products are available in other countries. The primary source of vitamin D in unfortified food is fish, with wild fish tending to have higher levels of vitamin D and omega 3 than farmed fish, due to differing food consumption. Egg yolks and livers also contain smaller amounts of vitamin D, while for vegans mushrooms grown under ultraviolet light contain vitamin D levels similar to fish though this product has yet to become widely available.  High levels of vitamin D supplementation can increase calcium deposition in soft tissues (hypercalcaemia) leading to renal and heart problems, so supplementation at more than 0.025 mg (I,000 IU) a day should only be undertaken with medical supervision, according to the UK Expert Group on Vitamins and Minerals. The risk of renal (kidney) stones may increase for some individuals at lower dosages (from around 400 IU), but on the whole vitamin D supplementation appears to lower risks of mortality.

1. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease Michael F Horlick American Journal of Clinical Nutrition, Vol. 80, No. 6, 1678S-1688S, December 2004 www.ajcn.org/cgi/reprint/80/6/1678S [outlines the role of sunlight in generating vitamin D and the food sources for vitamin D]

2.  Relation of Nutrition to Bone Lead and Blood Lead Levels in Middle-aged to Elderly Men: The Normative Aging Study Yawen Cheng, Walter C. Willett, Joel Schwartz, David Sparrow, Scott Weiss, and Howard H American Journal of Epidemiology Vol. 147, No. 12 www.aje.oxfordjournals.org/cgi/content/abstract/147/12/1162 [Finds that low Vitamin D is associated with higher bone lead levels and has more of an impact than calcium intake.]

3. Maternal Blood Lead Concentration, Diet During Pregnancy, and Anthropometry Predict Neonatal Blood Lead in a Socioeconomically Disadvantaged Population Lawrence M. Schell, Melinda Denham, Alice D. Stark,  Marta Gomez, Julia Ravenscroft, Patrick J. Parsons, Aida Aydermir, and Renee Samelson Environmental Health Perspectives Volume 111, Number 2, Feb 2003 www.pubmedcentral.nih.gov/picrender.fcgi?artid=1241350&blobtype=pdf [Finds that calcium is a slightly better predictor of blood lead but broadly agrees with the previous study. It must be noted that both studies are from the US where milk is routinely supplemented with vitamin D so a close relationship with calcium would be expected.]

4. Effects of Micronutrients on Metal Toxicity Marjorie A. Peraza, Felix Ayala-Fierro, David S. Barber, Elizabeth Casarez, and Leonard T. Rael Environ Health Perspect 106(Suppl 1):203-216 (Feb 1998). www.pubmedcentral.nih.gov/picrender.fcgi?artid=1533267&blobtype=pdf [Has a good, one paragraph summary of research on vitamin D and lead absorption on page 207 column 1]

5. Elevated Blood Lead Concentrations and Vitamin D Deficiency in Winter and Summer in Young Urban Children Kemp, Francis A; Netti, P; Howell, RW; Wenger, P; Louria; Bogden JD Environ Health Perspect Vol 115 No4, April 2007 www.ehponline.org/members/2006/9389/9389.pdf [Finds that vitamin D levels possibly contribute to seasonal variations in children’s blood lead levels with higher vitamin D levels associated with higher blood lead levels]

6. Serum Vitamin D Metabolites and Bone Mineralization in Young Children With Chronic Low to Moderate Lead Exposure Winston W.K. Koo, Susan K. Krug-Wispe, Jean J. Steinchen, Reginald C. Tsang, Paul A. Succop, Robert L. Bornschein, Omer G. Berger Pediatrics Vol. 87 No. 5 May 1991, pp. 680-687 http://pediatrics.aappublications.org/cgi/content/abstract/87/5/680 [Found that at blood lead levels below 20 µg/Dl lead did not have significant effects on 1,25-dihydroxycholecalciferol levels if levels of calcium, phosphorus and Vitamin D were adequate]

7. The Influence of Serum 25-hydroxy Vitamin D Levels on Helicobacter Pylori Infections in Patients with End-Stage Renal Failure on Regular Hemodialysis Hamid Nasri and Azar Baradaran Saudi Journal of Kidney Diseases and Transplants 2007:18(2):215-219 www.sjkdt.org/temp/SaudiJKidneyDisTranspl182215-8160448_224004.pdf  [Found a relationship between vitamin D levels and H. pylori infections]

8. Vitamin D Supplementation and Total Mortality Philippe Autier; Sara Gandini Arch Intern Med. 2007;167(16):1730-1737 www.direct-ms.org/pdf/VitDNonAuto/Autier Vit D and Mortality 07.pdf [finds that vitamin D supplementation, unlike most antioxidant supplementation, tends to reduce mortality rates]