Can vitamins & supplements help you stay well this winter?

With winter looming ahead, you want to know what you can do today to stay well — not just what to take when you're already sick. The idea that we get sick more often due to cold weather itself is not accurate. The "cold season" is tied to increased time indoors, allowing viruses to pass more easily from one person to another. To help you avoid illness, there are a few health factors to keep in mind during stressful cold weather months, like the busy holiday season.

While many foods and drink products claim on their labels to boost immunity, what actually supports your immune system are the vitamins and minerals you get as a benefit of a healthy, balanced diet. Eating plenty of vegetables and fruits, rich sources of antioxidants, is one quick and easy diet change that can pay off big in this regard.

Supplements can help some people get the recommended amounts of vitamins and minerals when they don't get enough from diet alone. In some cases, certain supplements may help support a healthy immune system.

Vitamin D. Most Americans get enough vitamin D through a combination of diet and sunshine. Although few foods contain this vitamin naturally, there are many foods fortified with vitamin D, such as milk, cereals and orange juice. However, some people, including breastfed infants, older adults, people with dark skin pigmentation and people with certain medical conditions, such as Crohn’s disease, celiac disease or ulcerative colitis, may not be getting enough vitamin D.  Also, during the dark winter months common in many U.S. states, it may be difficult to get enough vitamin D from sunshine. In such cases, you may want to consider increasing your intake of foods rich in vitamin D or taking a supplement.

Vitamin C. Studies aren't certain on the use of vitamin C to treat the common cold. Some show a decreased duration of cold symptoms, while others show no benefit at all. Products containing high dosages of vitamin C are widely available and promoted to help support your immune system, but be aware that the jury's still out on what impact they have on treating a cold. Also, note that the tolerable upper limit (UL) for vitamin C is 2,000 mg. Long-term intake above the UL may increase the risk of adverse side effects, such as kidney stones, diarrhea and abdominal bloating.

Zinc. Zinc is also found in cold and flu aisles. While it's essential for your immune system, the evidence on its benefits for treating colds is mixed. Some studies report that using zinc syrup or lozenges during the first few days of a cold may shorten the length of the cold. Other studies report no benefit. A diet rich in meat, fish and poultry, as well as whole grains and nuts, offers a great source of zinc. Also, many vitamin supplements include zinc. However, too much zinc can be dangerous, causing symptoms such as nausea, headaches and vomiting. Long-term use of high doses of zinc may even lead to lower immunity.

B vitamins. In general, a balanced diet will help ensure you get enough of the B vitamins you need for overall good health. Similar to zinc, it is important to remember that natural sources of vitamin B12 are only found in animal products, such as meat, poultry, eggs and dairy, so if your dietary preference doesn’t include these foods, you may want to take a supplement that includes a vitamin B complex.

Deficiency of B12 and other B vitamins may be linked to depression, although their role in depression isn't clear. If you're not getting enough in your diet, taking a supplement may help with so-called winter blues.

It’s possible to have too much of a good thing. Always read vitamin product labels so you don't take an unsafe dose, as this may lead to other conditions. For example, too much fat-soluble vitamins (vitamins A, D, E, K) can cause certain health problems.

Reading the labels also helps you see if the supplement meets United States Pharmacopeia (USP) standards.

Keep in mind that having healthy habits, including eating a wholesome diet and getting regular exercise, is a great way to keep your immune system strong year-round. If you have any questions about vitamins, supplements and how to stay healthy, talk to your healthcare provider or pharmacist.

Clinically reviewed and updated by Rebeca Thomas, BSN, RN, CPHQ, October 2022.