When to promote supplement use and when to curb it

A useful guide for addressing frequently asked questions

High doses of some manufactured vitamins are potentially harmful, say Harvard preventive health experts.

vitamins vs food

Writing in JAMA, they point out that recent trials suggest that exceeding the recommended daily allowance of beta-carotene, folic acid, vitamin E or selenium is associated with increased mortality, cancer and haemorrhagic stroke.

“Clinicians have an opportunity to promote appropriate use and to curb inappropriate use of micronutrient supplements, and these efforts are likely to improve public health,” write Dr JoAnn Manson and Dr Shari Bassuk.

They have compiled this supplement guide:

Circumstance Recommended supplementation
Pregnancy Folic acid, prenatal vitamins
Infants and children For breastfed infants, vitamin D until weaning and iron from age 4-6 months
Midlife and older adults Some may benefit from supplemental vitamin B12, vitamin D, and/or calcium
Bariatric surgery Fat-soluble vitamins, B vitamins, iron, calcium, zinc, copper and multivitamin/multimineral
Pernicious anaemia Vitamin B12 (1-2 mg/d orally or 0.1-1mg/mo intramuscularly)
Crohn's disease, other inflammatory bowel disease or coeliac disease  Iron, B vitamins, vitamin D, zinc and magnesium
Osteoporosis or other bone health issues Vitamin D, calcium and magnesium
Age-related macular degeneration Specific formulation of antioxidant vitamins, zinc and copper
Restricted or suboptimal eating patterns Multivitamin/multimineral, vitamin B12, calcium, vitamin D and magnesium
Long-term proton pump inhibitor use Vitamin B12, calcium and magnesium
Long-term metformin use Vitamin B12

Read the full study here