One good study, the Physicians’ Health Study II (PHS II), compared taking a multivitamin
to a placebo. After 12 years of follow up, those taking the multivitamin
had a modest 8% decreased risk of cancer incidence, mostly a decline in colorectal
cancer, but no effect on cancer mortality and no effect on the risk of prostate cancer,
heart attacks, strokes or cardiovascular deaths among male physicians, aged 65 or
older. The study suggests that there is little benefit to be gained from routine use
of multivitamins, but it is possible that a similar study among men who were less
healthy and well-nourished would have shown more benefit.

Editorial comment on the Physicians’ Health Study II noted that this single study
among physicians does not provide enough evidence to suggest taking multivitamins
for cancer prevention for various reasons, including that the majority of similar
studies suggest no effect of vitamin supplementation on cancer risk and some,
notably, show evidence of harm.

Some nutrition experts are more enthusiastic about multivitamins. Harvard professor
Walter Willett considers that there is evidence about the importance of vitamins
to the prevention of chronic diseases and that probably many people do not
get enough vitamins. He suggests that by increasing the amount of vitamins we
get, mostly from food, but maybe from supplements, we can improve our long-term
health. Some support for this position comes from the 2018 VITAL study that
found that supplementation with omega-3s and vitamin D did not significantly reduce
major cardiovascular events or total invasive cancer but that some subgroups
may have benefitted—more research is needed to determine the importance of these

Willett suggests taking a daily standard multivitamin-multimineral as “insurance”
against low levels of intake of eight vitamins that some people do not get enough
of in their diets. The recommended vitamins and minerals are beta-carotene, folic
acid, iron, zinc and vitamins B6, B12, D, and E. Because of poor absorption; vitamin
B12 deficiency occurs in about 3% and borderline deficiency in up to 20% of
persons over age 50. Vegans who eat no animal-derived foods are also at risk of
vitamin B12 deficiency.

This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel