Veggie Blog

Vitamins and your health

Can you get all your vitamins from food?

Most of us know that vitamins are part of a healthy, disease-free way of life. Vitamin products have also become far more specialized than they used to be, and many are aimed at particular parts of your body or your health. That does not mean everyone needs them. For most healthy people who eat a varied diet with plenty of vegetables, fruit, whole grains, beans, nuts and dairy or fortified foods, food covers vitamin needs. Multivitamins cannot take the place of the variety of foods in a healthy diet, according to the US National Institutes of Health.

Supplements are meant to fill gaps, not to replace meals. The tricky part is knowing whether you have a gap.

Who may need a supplement?

Some people do find it hard to get what they need from food alone. This is more likely if you follow a vegetarian or vegan diet, have food allergies or other dietary restrictions, have a small appetite so that you feel full quickly, are an older adult, are pregnant, or have a medical condition that affects how your body absorbs nutrients. Vitamin B12 is the best example for readers of this blog. It is found naturally in animal foods such as fish, meat, eggs and dairy products, but not in plant foods, so vegans in particular need fortified foods, such as some breakfast cereals and nutritional yeast, or a supplement. Adults need 2.4 micrograms a day, according to the NIH Office of Dietary Supplements.

If you are not sure, ask your doctor. A simple blood test can show whether you are low in a vitamin, and our post on whether vegetarians need vitamin supplements covers more of the basics.

What do the main vitamins do?

B12 helps to keep your nerves and blood cells healthy. Many people think that it boosts energy, but the evidence shows that extra B12 only improves energy and performance if you were short of it to begin with. Vitamin A supports vision and the immune system. Vitamin C helps your body heal wounds and absorb iron, and you can read about it in our post on why you need vitamin C and where to find it. Vitamin D works with calcium to keep bones strong. Vitamin E is an antioxidant, and our post on vitamin E explains what it does and how much you need. Taking more than you need does not give you extra health, and some vitamins can do harm in large doses.

What about selenium and colostrum?

Selenium is a mineral, not a vitamin. Adults need 55 micrograms a day, and most people in the United States get enough from food. People on vegetarian or vegan diets may have lower intakes, and Brazil nuts are particularly rich in it, so a few are enough. The upper limit is 400 micrograms a day, and chronic high intakes can cause hair and nail loss and other problems, which is why megadoses are a bad idea.

Colostrum, the first milk produced after birth, is sold as a supplement. It is not a vitamin, and studies in healthy adults have given limited and mixed results for immune support, so it is not something you need. The kind sold in supplements usually comes from cows, which matters if you are a vegan. Ask your doctor before adding it.

How do you decide?

Start with your diet, then talk to a doctor or pharmacist about anything you might be missing. If you do take a supplement, choose one that fits your age and needs, keep to the recommended amounts, and see our post on getting the right amount of vitamins. For tips on picking and using supplements, read our companion post on how to choose and use supplements wisely.

The old version of this post argued that you should eat antioxidant-rich vegetables, but that supplements are better than fruits and vegetables because they come without chemicals, sugar or calories, and it listed steak among the best sources of antioxidants. Those last claims are not supported by research, so I have rewritten the post around what is known about antioxidants in food and in pills.

What are antioxidants and where do they come from?

The National Center for Complementary and Integrative Health explains that our cells produce reactive substances during normal activity, and that excess of these substances can lead to “oxidative stress,” which may damage cells. Our bodies make some of the antioxidants they need. Others come from foods such as fruits, vegetables and grains. Some, including vitamins C and E and beta-carotene, are also sold as supplements. The old post is right that vegetables like broccoli, cauliflower, tomatoes and peppers are good choices, and the pigments that give plants their color are among the compounds researchers study.

Does eating colorful plants help?

There is strong evidence that people who eat more fruits and vegetables have a lower risk of chronic disease. The NCCIH points to a 2017 review of 95 observational studies, with more than 2 million participants in total, which found that higher intakes of fruits and vegetables were linked to lower risks of cardiovascular disease and cancer. It adds a caution: those people may also differ in other ways, such as being more active, and the benefit may come from other substances in the food, not from antioxidants alone. A practical rule is to fill half your plate with a mix of colors, and to include frozen vegetables, which are convenient and keep well.

Is organic produce higher in antioxidants?

The old post said organic fruits and vegetables have a “far higher” concentration. The real figure is more modest. A 2014 review of 343 studies in the British Journal of Nutrition found that antioxidant compounds were about 18 to 69 percent higher in organically grown crops, depending on the compound, and that detectable pesticide residues were found about four times as often in conventional crops (46 percent of samples compared with 11 percent). The review measured what is in the crops, not whether people who eat them are healthier. So if organic produce is affordable and you prefer it, there is a case for it; if it is not, ordinary fruit and vegetables are still worth eating. You can read the review abstract on PubMed.

Can supplements replace antioxidant foods?

No. The NCCIH reports that, except for age-related macular degeneration, there is currently no evidence that antioxidant supplements have a positive effect on cancer, heart disease, cataracts or other diseases of aging. High doses of beta-carotene may even increase the risk of lung cancer, especially in smokers and people exposed to asbestos, and in 2022 the U.S. Preventive Services Task Force recommended against beta-carotene and vitamin E supplements for preventing heart disease or cancer. Purified antioxidants do not behave like the mixture of substances in a whole food. The old post also claimed that supplements are better because fruits and vegetables carry chemicals and sugar. Plain fruit and vegetables do not need to be replaced by pills; if you buy canned ones, choose fruit packed in water or juice and vegetables without added salt, which is general nutrition advice, not a finding from the sources above.

What about meat and CoQ10?

The old post listed steak and meat as great sources of antioxidants and CoQ10 as a high-value supplement. The sources I checked name fruits, vegetables and grains as the main dietary sources, and I found no support for either claim, so I have dropped them. For more on supplements, read bee pollen and other antioxidant supplements, vitamin C and choosing vitamin supplements.

Walk down the vitamin aisle and you will see tablets, capsules, gummies, chewables, powders and liquids. About 57.6 percent of U.S. adults aged 20 and older used a dietary supplement in the past 30 days, according to a 2017 to 2018 survey by the National Center for Health Statistics, so this is a question many people have. Some sellers claim that liquid vitamins are far better absorbed. Let us see what holds up.

Do liquids work better than pills?

You may have read that about 90 percent of the nutrients in pills are not absorbed, and that liquids are far more effective. I could not find a reliable source for this. The NIH Office of Dietary Supplements lists tablets, capsules, gummies, powders and drinks as supplement forms, and does not rank one as better than the others. How much of a nutrient you absorb depends on the nutrient itself, the dose, how well the product is made, what you eat with it and your own body. A good tablet that breaks down properly is absorbed well, and a poorly made liquid may not be.

What are the real differences?

Liquids are useful if you cannot swallow pills. They need accurate measuring, and it is worth checking the label for added sugar and sweeteners. Chewables and gummies are easy to take, but many contain added sugar, and nutrient amounts vary from brand to brand, so compare the Supplement Facts panel. Because they can taste like candy, keep them out of the reach of children. Tablets and capsules are the most common form and are easy to store and dose, although some people find them hard to swallow.

Which form should you choose?

Choose one that you will take every day. A supplement in a drawer does nothing, so a form that is easy for you to swallow, chew or measure is a better choice than the “best” one that you skip. If you take a vitamin with fat in it, such as vitamin D, take it with a meal. Calcium and iron are better kept apart, as the Office of Dietary Supplements advises; our guide to calcium supplements has more. Check the Supplement Facts label for the amounts of each nutrient, and compare them to what you need.

How do you know that a product is good?

Several independent organizations test supplements and let products that pass display a seal. According to the Office of Dietary Supplements, the seal indicates that the product was properly manufactured, contains the ingredients listed on the label and does not contain harmful levels of contaminants, although it does not guarantee that the product is safe or effective. Use is common and rises with age, reaching 74.3 percent among adults 60 and older, so it is worth reading labels carefully if you take several products.

Do you need a supplement at all?

Most healthy people can get what they need from food. A supplement can help if you have a medical need, a restricted diet, or a deficiency that a doctor has found. For example, vegans need a source of vitamin B12. Ask your doctor or a dietitian before you buy, and read vitamins and your health and getting the right amount of vitamins. If you take medicine, check with your pharmacist first, because some supplements interact with drugs.

In short, form is a matter of convenience, taste and price. The quality of the product, the dose and the habit of taking it matter far more.