With thousands of supplements on the market, promising everything from weight loss to better sleep, it’s hard to know which products (if any) you should add to your regime.

If I could recommend just one supplement, it would be a general-purpose multivitamin and mineral, an all-encompassing supplement containing a broad range of nutrients that are necessary for normal functioning, growth and development.

If I’m recommending two or three supplements, I’ll often add fish oil and vitamin D3 to the mix.

The omega-3 fatty acids in fish oil (EPA and DHA) are essential for normal brain function, growth and development, and also for moderating inflammation. Deficiencies are linked to a greater risk of cardiovascular disease, certain cancers, mood disorders and inflammatory conditions.

Vitamin D is crucial for optimal bone health; it may also help prevent and treat conditions like diabetes, high blood pressure and multiple sclerosis. Optimal vitamin D levels can enhance athletic performance and might even protect against certain types of cancer.

The good news is that healthcare professionals can measure your levels of omega-3s and vitamin D via a 25-hydroxy vitamin D test to help determine if supplementation is necessary.

Do multivitamins really work?

When it comes to a multivitamin, however, things get a little more complicated.

Studies have shown no benefit of a multivitamins in terms of outcomes like longer lifespan or decreased risk of cancer and wellness experts disagree whether a multivitamin is necessary if a person eats a healthy, well-balanced diet. The Academy of Nutrition and Dietetics says the best nutritional strategy is to “wisely choose a wide variety of foods.”

While this is a noble nutritional goal, it’s not always realistic. People often get stuck in a routine, reaching for the same types of veggies, fruits, whole grains and protein sources for many of their meals and snacks. The result: They end up getting the same types of nutrients over and over again.

Even for those who do make a conscious effort to vary the foods they choose, it can still be quite challenging to get all of the necessary nutrients through diet alone, so I often recommend a multivitamin to my clients as a type of nutritional insurance, just in case they aren’t getting all of their nutrients through their diet.

But taking a multivitamin doesn’t mean you’re off the hook from eating fruits and vegetables. Supplements may supply many of the vitamins and minerals that we know about, but there are also loads of nutrients that exist in foods that scientists haven’t even identified yet, much less incorporated into nutritional supplements.

Suggested brands

If you decide to incorporate one of the abovementioned supplements into your regime, I recommend trying the following brands:

• Multivitamin: GNC Mega Men & GNC Ultra Mega Women
• Fish oil: Nordic Natural’s Ultimate Omega + D (includes D3 as well) and Carlson Labs
• Vitamin D3: No particular recommendation for this one, as there are many out there

Remember that supplements are just that: supplements — not substitutes — to an otherwise healthy lifestyle.

Be aware that supplements can interfere with certain medications or other supplements, so, as always, let your physician and healthcare professionals know what supplements you are taking and ask before adding any new products to your regime.