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The only exceptions are folic acid for pregnant women and, possibly, vitamin D — the studies are mixed on its benefits and risks. <<

It’s a closed book, except...

They don’t spend money on these studies. They spend money on drug studies.

The exceptions per the Linus Pauling Institute...

Women of childbearing age (folate, vitamin D, iron)
Pregnant and lactating women (vitamin B6, folate, vitamin D, iron)
People who consume <1,200 cal/day (multiple micronutrients)
Obese individuals (multiple micronutrients)
Infants, children, and adolescents (vitamin D)
People with dark-colored skin (vitamin D)
Those who cover all exposed skin or using sunscreen whenever outside (vitamin D)
Older adults (vitamin B12, vitamin D, zinc)
Low socioeconomic status (multiple micronutrients)
Patients who have had bariatric surgery (multiple micronutrients)
Patients with fat malabsorption syndromes (fat-soluble vitamins A, D, E, and K)
Alcoholics (vitamin A, B vitamins)
Smokers (vitamins C and E)
Vegans and those with limited intake of animal products (vitamin B12, vitamin D, calcium)
People taking medications that interfere with the absorption and/or metabolism of certain micronutrients (e.g., proton pump inhibitors used to treat heartburn may impair vitamin B12 absorption (36); frequent aspirin use can lower vitamin C status (37)).
People whose diets are not adherent to the USDA food plate (formerly food pyramid)—the vast majority of Americans (multiple micronutrients)

http://lpi.oregonstate.edu/infocenter/multivitamin-mineral.html

It’s a little more rigorous list.