Supplements for Adults: A Guide to Vitamins and Nutrients

Supplements are not one-size-fits-all. What works for one person may not be necessary for another. That said, with increased lifestyle changes, poor dietary habits, and more people interested in proactive wellness supplements have become popular in the last few years. With more additives and processed foods, certain nutrients are commonly lacking in modern diets. But it can be hard to know what supplements to add to one’s diet. 

Here’s a practical breakdown of the supplements many people may find helpful, how to take them, and what to keep in mind.

Vitamin D

Vitamin D supports bone strength, immune function, and muscle health. Since it’s fat-soluble, vitamin D should always be taken with food that contains fat for better absorption. Some people may need higher doses than others, but it’s best to confirm with a blood test and your doctor before supplementing heavily.

• Why: Supports bone strength, immune function, and mood.
• Who benefits: People with little sun exposure, older adults, and those with darker skin (who naturally produce less vitamin D from sunlight).

Magnesium 

Magnesium plays a role in hundreds of bodily processes, from muscle contraction and nerve signaling to energy production and sleep regulation. Unfortunately, many adults fall short of the recommended intake, especially if they don’t eat many leafy greens, nuts, or whole grains. Supplemental magnesium is often taken in forms like citrate or glycinate, which absorb well and are gentler on the stomach. Since magnesium can have a calming effect, many people prefer taking it in the evening to support relaxation and better sleep.

• Why: Important for energy production, muscle relaxation, heart health, and sleep quality.
• Who benefits: Many adults don’t get enough from food (especially if they eat little leafy greens, nuts, seeds, or whole grains).

Omega- 3 Fatty Acids (Fish Oil or Algae Oil)

Omega-3 fatty acids, found in fish oil and algae oil, support heart health, brain function, and help reduce inflammation. They are particularly important for people who don’t eat fatty fish like salmon, sardines, or mackerel regularly. A daily omega-3 supplement with EPA and DHA can help fill the gap and promote cardiovascular health. Taking it with meals that contain fat improves absorption. Algae-based options are available for vegetarians and vegans.

• Why: Support heart health, brain function, and reduce inflammation. 
• Who benefits: Anyone who rarely eats fatty fish (like salmon, sardines, or mackerel).

Multivitamin 

Multivitamins provide a broad mix of essential vitamins and minerals, making them a useful “safety net” for nutritional gaps. While they aren’t a substitute for balanced meals, they can help cover shortfalls if you skip food groups, have a limited diet, or simply want reassurance that you’re meeting basic needs. Since they contain fat-soluble vitamins like A, D, E, and K, multivitamins are best taken with a meal that includes some healthy fat. Taking them with food also reduces the chance of nausea.

• Why: Provides a broad safety net for micronutrients you may miss in your diet. 
• Who benefits: People with restricted diets (vegan, vegetarian, low-calorie, or limited food variety).

Vitamin C 

Vitamin C is a water-soluble antioxidant that helps the body form collagen, heal wounds, and absorb iron from plant foods. It also supports immune health, though it’s not a cure-all for colds. Since the body doesn’t store vitamin C, daily intake is important. Supplements can be taken with or without food, but dividing doses into smaller amounts throughout the day may reduce stomach upset. While most people can get enough from fruits and vegetables, supplements are a safe option if your diet is lacking.

• Why: Acts as an antioxidant, supports the immune system, helps the body make collagen, and boosts absorption of plant-based iron.
• Who benefits: People who eat few fruits and vegetables, smokers (who need more vitamin C), athletes or those under physical stress, individuals with iron-deficiency anemia, and people recovering from wounds or surgery.

Vitamin B12

Vitamin B12 is critical for making red blood cells, supporting energy metabolism, and protecting nerve health. While it’s abundant in animal products, deficiency is common in vegetarians, vegans, and older adults, since absorption declines with age. Supplements are available in tablets, capsules, or sublingual forms. Unlike fat-soluble vitamins, B12 can be taken on an empty stomach, though some people prefer it in the morning since it may provide a natural energy boost.

• Why: Supports red blood cell production, nerve function, and energy metabolism. 
• Who benefits: Vegans, vegetarians, and older adults (absorption decreases with age).

Turmeric 

Turmeric is a popular herbal supplement thanks to curcumin, its active compound with anti-inflammatory and antioxidant properties. It’s often used to support joint comfort and reduce inflammation. However, curcumin is poorly absorbed on its own, so look for supplements that contain black pepper extract (piperine) or specialized delivery forms that boost absorption. Always take turmeric with food, ideally one that includes fat, to maximize effectiveness.

• Why: Curcumin, turmeric’s active compound, has anti-inflammatory and antioxidant properties that may ease joint pain and support overall wellness.
• Who benefits: People with osteoarthritis or rheumatoid arthritis, those experiencing chronic inflammation, and adults looking for a natural alternative to manage mild joint discomfort.

Probiotics

Probiotics are beneficial bacteria that support gut health, digestion, and may play a role in immunity. While they aren’t strictly necessary for everyone, many adults benefit from them — especially those who have taken antibiotics, struggle with digestive issues, or don’t eat fermented foods like yogurt, kefir, or sauerkraut. They’re usually best taken with food to help the live bacteria survive stomach acid and reach the intestines.

• Why: Support gut health, digestion, and may play a role in immunity.
• Who benefits: People who frequently take antibiotics, have digestive issues, or don’t eat many fermented foods

While supplements can be beneficial, they work best when targeted to your actual needs. Remember that supplements should complement, not replace, a healthy diet. It’s also a good idea to introduce one supplement at a time so you can monitor its effects. Before starting anything new, talk to your healthcare provider to make sure it’s safe and appropriate for your health needs.