Can one daily multivitamin help you remain active and independent as you grow older? New research offers a cautiously encouraging answer. In a large randomized study, adults age 60 and older who took a daily multivitamin for three years reported slightly better functional health than those who took a placebo. Functional health includes how well you manage everyday activities and how much symptoms interfere with daily life.

The study included more than 16,000 participants from the COSMOS trial. The differences were modest and were measured with questionnaires rather than objective physical tests. The findings were presented at the NUTRITION 2026 conference but have not yet been published in a peer-reviewed journal. They are interesting, but they do not prove that a multivitamin prevents disability or treats fatigue, shortness of breath, or swelling in the feet. New or worsening symptoms like these require medical evaluation. ¹

A multivitamin can help fill nutritional gaps, especially when appetite, food choices, medications, or changes in digestion make it difficult to obtain enough nutrients. It cannot replace a varied diet, exercise, sleep, prescribed treatment, or regular eye care. Evidence also does not show that routine multivitamin use prevents every chronic disease. The most sensible goal is nutritional support, not a promise of disease prevention. ²

Why B Vitamins Matter to Your Eyes and Nervous System

This article focuses on the B vitamins found in many multivitamins. These nutrients help your cells release energy from food, make DNA and red blood cells, regulate homocysteine, and maintain the nervous system. Vitamin B12 also helps maintain myelin, the protective coating around many nerves. Your eyes rely on these basic processes every moment, particularly in the retina and optic nerve. ³

B vitamins are essential, but that does not mean that large doses prevent or treat eye disease. Much of the research concerns associations, nutrient deficiencies, laboratory experiments, or animal models. Results from these studies help researchers decide what to test next, but they do not automatically become treatment recommendations for people.

Mitochondria Energy and Oxidative Stress

The retina and optic nerve use a great deal of energy. Mitochondria, often described as the power centers of cells, produce most of that energy. Vitamins B1 and B2 help enzymes involved in mitochondrial energy production. Vitamin B3 helps the body make NAD+, a molecule that participates in energy metabolism and cellular repair.

Aging and chronic oxidative stress can reduce the availability of NAD+. Researchers are studying whether supporting NAD+ metabolism could protect retinal ganglion cells and other vulnerable tissues in glaucoma and age-related macular degeneration. Most evidence in this area remains preclinical, and researchers have not established that high-dose vitamin B3 or an NAD+ supplement can prevent or treat these diseases in people. ⁴

Mitochondria also produce reactive oxygen species during normal energy generation. When the body cannot adequately control these unstable molecules, oxidative stress can damage fats, proteins, and DNA. Oxidative stress is involved in many eye conditions, including macular degeneration, glaucoma, diabetic retinopathy, cataracts, and dry eye disease. B vitamins support normal cell metabolism, but they are only part of the body’s much larger antioxidant and repair systems.

What Research Suggests About Specific Eye Conditions

Age Related Macular Degeneration

One of the strongest human studies followed women at high cardiovascular risk for an average of 7.3 years. Participants who received folic acid, vitamin B6, and vitamin B12 had a 34% lower relative risk of developing age-related macular degeneration than those who received a placebo. The study did not show that these vitamins reverse existing macular damage, and the results may not apply equally to men or to people with different health profiles. ⁵

Glaucoma

Nicotinamide, a form of vitamin B3, helps the body produce NAD+. In glaucoma-prone mice, high-dose nicotinamide protected retinal ganglion cells and the optic nerve. This finding generated interest in human research, but a mouse study cannot establish a safe or effective dose for people. High-dose nicotinamide should not be used for glaucoma without supervision from an eye doctor and another qualified healthcare professional. ⁶

Diabetic Retinopathy

B-vitamin research in diabetic retinopathy includes several different kinds of evidence. An analysis of national survey data found that higher dietary vitamin B6 intake was associated with a lower likelihood of diabetic retinopathy. Other studies have reported lower levels of thiamine, folate, or vitamin B12 in some people with diabetes or diabetic retinopathy. Association does not prove that a deficiency caused the eye disease or that supplementation will prevent it. ⁷

Laboratory and animal studies also suggest that vitamins B1, B9, and B12 may influence inflammation, oxidative stress, blood-retinal barrier function, or retinal thinning in diabetes. These results are useful for research, but they do not replace blood sugar control, blood pressure management, prescribed treatment, or dilated eye examinations.

Cataracts

The evidence concerning B vitamins and cataracts is mixed. In the Age-Related Eye Disease Study, some B-vitamin intakes were associated with a lower risk of certain cataract types, while the highest folate intake was associated with a higher risk of mild posterior subcapsular cataract. These observational findings do not show that folate caused cataracts, but they are a reminder that more is not always better. ⁸

Dry Eye and Corneal Health

In the Blue Mountains Eye Study, dietary intake of several nutrients was associated with dry eye symptoms. Participants with the highest vitamin B12 intake were less likely to report more than two dry eye symptoms than those with the lowest intake. This was an observational study, so it cannot prove that B12 prevented dry eye. ⁹

Small clinical studies have also examined oral vitamin B1 and methylcobalamin, a form of B12, for dry eye disease and neuropathic ocular pain. Some participants reported symptom improvement, and researchers observed changes in corneal nerves. These early findings need confirmation in larger trials. B vitamins should not replace artificial tears, prescription treatment, or an evaluation for persistent pain, light sensitivity, or blurred vision. ¹⁰

Getting B Vitamins From Food

Good food sources of B vitamins include fish, shellfish, eggs, dairy products, poultry, meat, beans, lentils, whole grains, and leafy green vegetables. Different foods supply different B vitamins. Leafy greens, for example, can provide folate, but they do not provide the full B-complex spectrum.

Vitamin B12 occurs naturally mainly in animal foods. If you eat little or no animal food, look for B12-fortified nutritional yeast, plant-based milk, breakfast cereal, or other fortified foods. Check the Nutrition Facts label carefully, since not every nutritional yeast or plant-based product contains vitamin B12.

Why Diet Alone May Not Prevent B12 Deficiency

You can eat plenty of meat or other B12-rich foods and still become deficient if your body cannot absorb the vitamin properly. This becomes more common with age. Pernicious anemia, digestive disorders, and some stomach or intestinal surgeries can also interfere with absorption.

Medications matter as well. Metformin can reduce vitamin B12 absorption and lower blood levels of the vitamin. Proton-pump inhibitors and other acid-reducing medicines can make it harder to release B12 from food. Some antiseizure medicines, including drugs that are also prescribed for mood disorders, may affect folate or other B vitamins. If you use these medicines long term, ask your healthcare professional whether your vitamin B12 and folate levels should be checked. Do not stop or change a prescription medicine on your own. ¹¹

Vitamin B12 deficiency may cause fatigue, weakness, numbness, tingling, balance problems, memory changes, or other neurological symptoms. Nerve problems can occur even when a person does not have anemia, so a normal blood count does not always rule out a deficiency. A healthcare professional may consider tests such as serum B12, methylmalonic acid, and homocysteine when symptoms and risk factors warrant further evaluation.

Choosing Supplements Carefully

Unless your doctor, nutritionist, or another qualified healthcare professional recommends otherwise, avoid taking a high-dose individual B vitamin on its own for routine, long-term use. B vitamins participate in overlapping metabolic pathways, and large amounts of one vitamin can create problems. Too much vitamin B6 can damage nerves, while high folic acid intake can hide the anemia caused by vitamin B12 deficiency without preventing neurological damage. A balanced B-complex supplement or multivitamin is generally a more sensible choice for routine nutritional support. ¹²

Look for doses that stay reasonably close to daily nutritional requirements unless a healthcare professional is treating a documented deficiency. Review the label with your doctor or pharmacist if you take prescription medicines, especially warfarin, thyroid medicine, diabetes medicine, or other drugs that can interact with nutrients. Bring a complete list of supplements to medical appointments.

The Practical Takeaway

A multivitamin may help fill nutritional gaps, and preliminary research suggests that it may modestly support functional health in some older adults. B vitamins deserve attention because they help maintain energy metabolism, blood cells, nerves, and myelin. Research also points to possible relationships with several eye conditions, although the strength of the evidence varies widely.

Your best foundation remains a varied diet, regular movement, adequate sleep, control of cardiovascular and blood sugar risks, and routine eye examinations. A supplement can support that foundation. It cannot replace it.

Favorite Products for Overall Eye Health and Brain

Dr. Grossman’s Complete Eye Formula 2oz (oral spray)

Advanced Eye and Vision Support Formula – our whole food, organic, GMO free formula with lutein and zeaxanthin. 

Dr. Grossman’s Bilberry/Ginkgo Combination 2oz (60ml)

Dr. Grossman’s Meso Plus Retinal Support and Computer Eye Strain Formula with Astaxanthin 90 vcaps -with lutein, zeaxanthin, mesozeaxanthin and astaxanthin

Wonderfeel NMN capsules 60 vegcaps – NMN is rapidly absorbed and converted to NAD+ (Nicotinamide adenine dinucleotide) production.

Dr. Grossman’s Whole Food Organic Superfood Multi-Vitamin 120 Vcaps -our organic, whole food, GMO free multivitamin

Dr. Grossman’s Whole Food Combo 2-Month Special – includes 2 bottles of the Advanced Eye and Vision Support formula and 2 bottles of Dr. Grossman’s Whole Food Organic Superfood Multivitamin.

Packages

AMD Package 1 (3-month supply)

Brain and Memory Support Package 1

Sugar Balance & Blood Vessel Support Package 1 (1 month)

Mitochondria Eye Brain Support Package

Books

Natural Eye Care: Your Guide to Healthy Vision and Healing

Natural Brain Support: Your Guide to Preventing and Treating Alzheimer’s, Dementia and Other Related Diseases

Natural Parkinson’s Support: Your Guide to Preventing and Managing Parkinson’s