I noticed that a mineral supplement I have been taking contains
aluminum.  I have heard that aluminum is linked with alzheimers. 
Should aluminum be part of a mineral supplement?  What role does it
perform and what should I watch out for?

Hi danousd-ga
I performed searches on various combinations of Aluminium, nutrition,
supplement, deficiency, toxicity, symptoms, dietary requirement.

----------
Deficiency
----------
1) Except those related to alternative medicines, no website stated
that Aluminium is a required nutrient for humans. Some clearly said
that Aluminium is not a proven nutrient.
---
http://www.tracemin.com/why_use_mineral_analysis.htm
---
http://www.merck.com/mrkshared/mmanual/section1/chapter1/1a.jsp
See under Micronutrients
"..... Other trace minerals implicated in animal nutrition (ie,
aluminum, arsenic, boron, cobalt, nickel, silicon, and vanadium) have
not been established as being required by humans. ...."
---
http://www.emedicine.com/med/topic113.htm
"... No known physiologic need exists for aluminum;  ..."
--------
Toxicity
--------
It is easier to find literature on Aluminium toxicity. 
1) High concentrations of Aluminium are well tolerated and it's cause
of concern only in persons with renal disabilities.
http://www.crescentlife.com/dietnutrition/a_to_z.htm
http://www.emedicine.com/med/topic113.htm
2) Link between Aluminium and Alzheimers is not proven yet, though
evidence exists that they are linked.
http://cesantabarbara.ucdavis.edu/ffsum98.htm

I Would be glad to answer if you have any further questions.
Regards.
---
NOTE:
I am not a medical professional, by education or by profession, and am
not qualified to offer medical advice. My comment is based solely on
the searches I performed on the internet so do not make any decision
on its basis.
---

Hi danousd-ga
I performed searches on various combinations of Aluminium, nutrition,
supplement, deficiency, toxicity, symptoms, dietary requirement.

If you are satisfied, please let me know if I can post this comment as an answer.
----------
Deficiency
----------
1) Except those related to alternative medicines, no website stated
that Aluminium is a required nutrient for humans. Some clearly said
that Aluminium is not a proven nutrient.
---
http://www.tracemin.com/why_use_mineral_analysis.htm
---
http://www.merck.com/mrkshared/mmanual/section1/chapter1/1a.jsp
See under Micronutrients
"..... Other trace minerals implicated in animal nutrition (ie,
aluminum, arsenic, boron, cobalt, nickel, silicon, and vanadium) have
not been established as being required by humans. ...."
---
http://www.emedicine.com/med/topic113.htm
"... No known physiologic need exists for aluminum;  ..."
--------
Toxicity
--------
It is easier to find literature on Aluminium toxicity. 
1) High concentrations of Aluminium are well tolerated and it's cause
of concern only in persons with renal disabilities.
http://www.crescentlife.com/dietnutrition/a_to_z.htm
http://www.emedicine.com/med/topic113.htm
2) Link between Aluminium and Alzheimers is not proven yet, though
evidence exists that they are linked.
http://cesantabarbara.ucdavis.edu/ffsum98.htm

I Would be glad to answer if you have any further questions.
Regards.
---
NOTE:
I am not a medical professional, by education or by profession, and am
not qualified to offer medical advice. My comment is based solely on
the searches I performed on the internet so do not make any decision
on its basis.
---

I noticed that the article from the Fast Facts newsletter from UC
Davis is dated February 1998.  Could you find a more recent article on
the link between alzheimers and aluminum?

Go ahead and post this as the answer.  Your research was clear and
helpful.  You did a good job.

I searched a few medical journals and found more links. Most of them
are quite technical so please let me know if you want them.

Key points:
* An article as recent as in Jan 2005 says that link between
Aluminium(Al) and Alzheimers Disease(AD) is not confirmed.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15666086&query_hl=11

* Other than renal diseases, Aluminium is linked to various bone
related and neurological disorders also.
* Calcium can help reduce concentration in the blood and toxic effects
of Aluminium.
* In some studies significantly higher Al and lower Mg and P values
were found in some AD brain regions compared to the controls.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16131728&query_hl=11

* Silica in drinking water may reduce the risk of developing AD in elderly women. 
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15817869&query_hl=11
------------------------------------

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16146022&query_hl=7

Aluminum hemotoxicity mechanisms.
Osinska E, Kanoniuk D, Kusiak A.
Institute of Rural Medicine, Lublin.
Both aluminum and its salts are commonly used by people. Aluminum
salts are components of drugs. Such a widespread use of aluminum was
enhanced by the belief that it is not toxic and is quickly excreted
from the body with urine. It turned out, however, that this element
has a negative impact on human health. Post-dialysis encephalopathy of
patients with kidney malfunctioning was ascribed to the presence of
aluminum in dialysis fluid. Aluminum cumulating in brain tissue is
claimed to play a role in developing neurological disorders. This
element affects bones as well as it causes disturbances in phosphorus
and calcium levels, which is demonstrated chiefly by osteomalatia.
Aluminium accumulation in the liver leads to cholestasis. This element
causes numerous changes in peripheral blood and hemogenic system. It
also causes normo- or microcytary anemia as it disturbs maturing of
erythroblastic series cells and heme biosynthesis; it decreases
osmotic resistance of red blood cells. Aluminum inhibits defensive
mechanisms connected with white blood cells and macrophages. A number
of processes, namely aluminum's hemolytic activity, blood cells'
shorter lifetime or disturbed erythropoiesis process, are responsible
for hematological changes.
----------------------------

Thanks for the tip and the rating!