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Health Shot: Vitamin Overdose

January 17, 2020

Too much of a good thing is even better? Right? Wrong. Turns out with vitamins, this is not the case. The Vitamin market is a $23.3 Billion industry, and we are increasingly turning to these convenient capsules for a quick fix. The effect of vitamins is a U curve – too little has negative effects, but so does too much. A moderate amount has the best effects on the body – but this can be hard to achieve with vitamin supplements. Vitamins usually have 1-10x the recommended daily allowance in their pills, and people take these without question. With public opinion largely being that vitamins are a revolution, I want to shed some light on how overdosing on some of the most popular supplements can have detrimental effects.

Vitamin D

Vitamin D manages calcium in your blood, bones and gut and helps cells all over your body to communicate properly. Since the rise of sedentary lifestyles, many have been turning to Vitamin D supplements over being outside in the sun. Large overdoses of vitamin D (100x the daily allowance for many months) can cause calcium buildup in the blood, called Hypercalcemia This buildup can result in persistent nausea and frequent vomiting. Additionally, the calcium buildup in the blood can cause kidney damage when the calcium binds with phosphate and forms crystals in tissues. In a case series conducted in Kashmir, India, researchers found that the Vitamin D prescribed by physicians to treat deficiencies was far exceeded the required daily amount, and pushed patients to hyperclacemia. In their conclusions, the researchers cautioned against taking a seemingly innocuous vitamin in large doses.

Vitamin A

Vitamin A is important for eye heath and helps prevent eye diseases like Age-related macular degeneration. However, Acute Vitamin A toxicity can occur when a single excessively high dose and chronic toxicity when 10x the recommended daily amount is taken over a long period. Side effects can include headaches, vision disturbances, joint pain, and skin irritation. Worse, toxicity can impact fetal health and even cause birth defects of the  eye, skull, lungs, and heart. The national institutes of health warns pregnant women about taking high dose Vitamin A supplements.

Vitamin E

Vitamin E is important to important to vision, reproduction, and the health of your blood, brain and skin. In a clinical trial called SELECT (Selenium and Vitamin E Cancer Prevention Trial), 35,000 men 50 years and older took Vitamin E  and Selenium supplements for 5.5 years and then were observed for 1.5 years following. Men tho took Vitamin E supplements alone had a 17% increased risk of prostate cancer compared to men on the placebo pill. Men taking vitamin E and selenium both also had an increased risk of prostate cancer, but in lower amounts. After analyzing the results, the SELECT team concluded that the vitamin dose (400IU/day) given was far too high based on the U shaped curve. The recommendation from the SELECT team was that men should not take vitamin supplements for cancer prevention.

The Takeaway

As the negative repercussions of vitamin overdoses continue to come to light, researchers are starting to question the practice of prescribing vitamins to those with deficiencies in high doses. As consumers of vitamins, we have the responsibility to ensure that we are getting our vitamins in reasonable quantities through vitamins or sticking to natural sources. Next time you decide to pop a pill, you might want to flip the bottle around and get a better look at what you’re having!

 

Sources:

Nicastro, H. L., & Dunn, B. K. (n.d.). CHAPTER 25. The Selenium and Vitamin E Cancer Prevention Trial (SELECT): Prevention of Prostate Cancer Using Selenium and/or Vitamin E in the SELECT Cancer Prevention Trial. Food and Nutritional Components in Focus Selenium,428-457. Retrieved from https://epi.grants.cancer.gov/Consortia/members/select.html.

Office of Dietary Supplements – Vitamin A. (n.d.). Retrieved from https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/

Penniston, K. L., & Tanumihardjo, S. A. (n.d.). Vitamin A in dietary supplements and fortified foods: Too much of a good thing? Journal of the Academy of Nutrition and Dietetics. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12963949.

Trend Insights: Vitamins & Supplements. (n.d.). Retrieved from https://www.fona.com/trend-insights-vitamins-supplements/.

 

 

 

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  Timothy Durham was convicted of rape when a test showed his DNA genotype matched the DNA recovered from the crime scene. Eye witnesses testified that Durham was in a different state at the time of the incident, but he wasn’t exonerated from his 3000 year sentence until follow up DNA analysis showed that the preliminary forensic analysis used in the trial was misinterpreted (Thomas et al.). DNA testing serves an invaluable part in our criminal justice system, but it comes with complications and bias that can lead to wrongful convictions and misinformed juries.  

Background:

Forensic genetics aims to identify the origin of a biological sample. It can be traced back to Karl Landsteiner who discovered human ABO blood groups. With blood groups, suspects could be eliminated based on their blood type. For example, if a suspect had type A blood and there was type B blood left at the scene by the perpetrator, the investigators could rule out the suspect. Unfortunately, the reverse didn’t work. If the suspect and perpetrator both had the same blood type, it can’t be concluded that the suspect was guilty. Blood identifiers evolved into 8 distinct categories which improved the ability to eliminate suspects, but could only conclude that (if the system matched) it might be the perpetrator or this person might be related to the perpetrator (Jobling and Gill). The field evolved in the 1980s with the discovery of Minisatellites, lines of repetitive DNA that don’t encode proteins. Minisatellite patterns in DNA create what we know today as the DNA fingerprint, and it has a much higher accuracy rate than previous methods (Augustyn et al.). Around the same time, a breakthrough for victims of sexual assault was discovered. In the case of assault, bodily fluids of both the victim and the assaulter can get mixed. A process called differential lysis was created which could selectively increase the concentration of sperm in a fluid sample thereby allowing for accurate DNA testing (Jobling and Gill). Forensics evolved to use single-locus probe testing after several years because of its ease of interpretation. It looked at specific minisatellites that had high variability between subjects. This was the first DNA-based method to be used in a criminal investigation. Two murder homicides from several years apart were connected using DNA evidence. The evidence was then used to exonerate an innocent man, and the guilty party was found when he tried to evade mandatory DNA testing for all men in the small town. His guilt was then reinforced when the DNA profiles matched, and he gave a confession (Jobling and Gill). Finding DNA at a crime scene doesn’t guarantee that you’ll find a murderer. There are issues with non-pure samples and limited samples that make DNA work difficult, and accreditation of facilities and new techniques and take time (Jobling and Gill).  

Subjectivity of DNA Interpretation:

In a 2009 publication, the National Academy of Science discusses the possibility for subjective influence in lab based forensics. The interpretation bias happens in complex cases where, for example, there could be a mixture of DNA. A study published in 2011 looked specifically at this issue. A gang rape happened in Georgia, and the mixture in DNA from the case was used to prosecute one suspect after another suspect took a plea bargain to testify against him. With DNA mixtures, there are three possible conclusions: suspect excluded, suspect cannot be excluded, and inconclusive. If the suspect is excluded, it means that there’s little to no possibility that his DNA is part of the sample. If the suspect cannot be excluded, it means that there’s a possibility that his DNA is part of the sample. In the trial, the DNA examiners who knew the context of the case concluded that the suspect being prosecuted could not be excluded. The 2011 study gave the DNA evidence from this case and the DNA profiles of the suspects to 17 forensic examiners. These examiners had no context of the case, and they all worked independently. Of the 17, only 1 came to the same conclusion (suspect cannot be excluded) as the examiners who knew the context of the case. Twelve of the 17 concluded that the suspect who was prosecuted and convicted had no relation to the DNA found in the sample. Not only does this show that subjectivity occurs due to the context of the case, but the 17 examiners came up with different findings based on their past experiences meaning that not all DNA analysis is objective. Some organizations like the Scientific Working Group on DNA Analysis Methods say that quantitative statistical evidence should be presented with every categorical conclusion, but the US doesn’t require this (Dror and Hampikian).

False Positives:

There are two categories that cause wrongful identification in a DNA report: coincidental matches and false positives. Coincidental matches are DNA matches between two unrelated people. The probability of these matches is about 1 to 500,000 for white individuals and about 1 to 350,000 for black individuals. This small probability of coincidental matches makes people feel confident in DNA evidence. False positives, on the other hand, are matches between DNA and test DNA that result from issues in the forensics lab. There have been multiple cases of forensics labs accidentally switching victim and suspected rapist DNA which lead to convictions that were later overturned when the lab realized the error. There are also cases of misreading or misunderstanding a sample. In a case from 1993, a man was convicted of rape because someone interpreted a mixed sample of victim and perpetrator DNA as an individual sample. The conviction was again overturned. To prevent false convictions, retesting DNA is allowed, but it’s not an efficient solution. Many people are pushing for statistical information on the probability of false positives, so that the jurors can make accurate judgements based on DNA evidence (Thomas et al.).  

Conclusion:

DNA analysis is a useful tool for the criminal justice system, but subjectivity can be an issue in forensic testing. To combat wrongful convictions, there are organizations like The Innocence Project who use DNA testing to free the innocent, but reformed forensic testing standards should be put in place to prevent subjectivity and to ensure juries are correctly informed during trials. https://www.innocenceproject.org/    

Citation:

Augustyn , Adam, et al. “DNA Finerprinting.” Encyclopedia Britannica , 26 Apr. 2018, www.britannica.com/science/DNA-fingerprinting#ref153186. Dror, Itiel E., and Greg Hampikian. “Subjectivity and Bias in Forensic DNA Mixture Interpretation.” Science & Justice, vol. 51, no. 4, 2011, pp. 204–208., doi:10.1016/j.scijus.2011.08.004. Jobling, Mark A., and Peter Gill. “Encoded Evidence: DNA in Forensic Analysis.” Nature Reviews: Genetics, vol. 5, no. 10, Oct. 2004, pp. 739–751., doi:10.1038/nrg1455. Thompson, William C, et al. “How the Probability of a False Positive Affects the Value of DNA Evidence.” Journal of Forensic Sciences, vol. 48, no. 1, Jan. 2003, pp. 1–8., doi:10.1520/jfs2001171.