Why Are Vitamins Important?
Vitamins are essential nutrients that help our bodies function normally.
They support our bones, nerves, immune system, blood cells and many processes involved in maintaining health.
Most vitamins must come from food because the body cannot produce enough of them.
Although we need only small amounts, vitamin deficiencies can have important consequences.
In longevity discussions, vitamins are frequently promoted for energy, immunity, brain health and slowing aging. But their established benefits should be distinguished from claims that have not been confirmed in clinical studies.
Vitamin D: Bones, Muscles and Immunity
Vitamin D helps the body absorb calcium and maintain healthy bones. It also contributes to muscle and immune function.
The body produces vitamin D when the skin is exposed to sunlight. Smaller amounts come from foods such as oily fish, eggs and fortified products.
Inadequate vitamin D status is more common in people with limited sunlight exposure, certain medical conditions or impaired absorption.
Correcting deficiency is important, particularly for bone health.
However, high-dose vitamin D supplementation has not been shown to extend human lifespan or consistently prevent age-related diseases in otherwise healthy adults.
Vitamin B12 and Other B Vitamins: Nerves and Metabolism
Vitamin B12 supports nerve function, red blood cell production and DNA synthesis.
Deficiency may cause anemia, numbness, balance difficulties and sometimes problems with memory or concentration.
Older adults may have reduced vitamin B12 absorption. People taking metformin or certain acid-suppressing medications may also be at increased risk.
Other B vitamins, including B6 and folate, contribute to energy metabolism and normal nervous system function.
They also help regulate homocysteine, a substance associated with cardiovascular risk when elevated.
However, lowering homocysteine with supplements does not necessarily prevent cognitive decline or cardiovascular disease.
Vitamins A, C and E: Cellular Protection
Vitamin A supports vision, immune function and normal cell development.
Vitamin C is needed for collagen formation, wound healing and normal immune function.
Vitamin E helps protect cell membranes against oxidative damage.
Vitamins C and E are frequently marketed as antioxidants that may slow aging.
However, taking high doses has not been shown to extend human lifespan.
Excessive vitamin A intake can be toxic, and high-dose vitamin E supplementation may increase certain health risks.
Obtaining these nutrients through a balanced diet is generally preferable to unnecessary high-dose supplementation.
Vitamin K: Blood Clotting and Bone Health
Vitamin K is essential for normal blood clotting and contributes to proteins involved in bone metabolism.
Green leafy vegetables are an important source of vitamin K1.
Vitamin K2 is found in certain fermented foods and animal products.
Vitamin K2 supplements are increasingly promoted for bone and cardiovascular health, but evidence for broad anti-aging benefits remains insufficient.
People taking vitamin K antagonist anticoagulants, such as warfarin, should maintain consistent vitamin K intake and discuss major dietary or supplement changes with their clinician.
Do We Need Vitamin Supplements as We Age?
Some people benefit from supplementation because of deficiencies, dietary restrictions or medical conditions.
Examples include vitamin B12 for people with impaired absorption or diets excluding animal products, and vitamin D when supplementation is indicated by individual circumstances or applicable guidelines.
However, routine high-dose vitamin supplementation has not been shown to extend lifespan in generally well-nourished adults.
More is not always better.
The most effective approach is to maintain adequate vitamin intake and correct deficiencies when necessary.
Based on Research
European Food Safety Authority (EFSA). Dietary Reference Values for Nutrients. https://www.efsa.europa.eu/en/topics/topic/dietary-reference-values
National Institutes of Health, Office of Dietary Supplements. Vitamin and Mineral Fact Sheets. https://ods.od.nih.gov/factsheets/list-all/
Volkert D, Beck AM, Cederholm T, et al. ESPEN practical guideline: Clinical nutrition and hydration in geriatrics. Clinical Nutrition, 2022. https://doi.org/10.1016/j.clnu.2022.01.024
