Recommendations are based on current scientific evidence, safety profile, and feasibility of obtaining the nutrients through whole foods.
Supplements in this category are generally recommended because they are hard to get enough of from food alone or because correcting a deficiency shows significant benefit.
Rationale and Usage: Acts more like a hormone and is essential for regulating hundreds of bodily processes. It's difficult to get enough from food or sunlight alone. Correcting a deficiency is linked to stronger bones, fewer fractures, and possibly fewer infections. Testing levels is recommended to determine necessity. Recommended intake is 400 IU to 2,000 IU per day (Vitamin D3 with Vitamin K2).
Rationale and Usage: Best evidence supports its benefit for heart health, with possible extra benefits for brain, mood, and inflammatory conditions. Recommended if you are not eating oily fish (salmon, sardines, etc.) two to three times a week. Vegans and vegetarians are highly recommended to source from algae. It's difficult to get over a gram of EPA and DHA from food alone. Look for third-party testing to ensure quality and prevent rancidity.
These supplements may be beneficial for certain people (e.g., athletes, older adults) or can serve as a backup, but optimizing whole foods should be the first priority.
Rationale and Usage: Recommended particularly if you exercise regularly. It's well-studied with a good safety profile, helping the body produce quick energy for short, intense activities. Emerging evidence suggests benefits for older adults (for brain protection) and vegans/vegetarians. Usual dose is 3 to 5 grams daily.
Rationale and Usage: Essential for muscle/nerve function and blood pressure. Research on supplements is weak overall, but may offer small benefits for older adults and people who train extremely hard. Optimizing meals with magnesium-rich foods (nuts, seeds, greens) is the best starting point. Caution: high doses can cause diarrhea or interact with medications.
Rationale and Usage: Recommended to try if advised for a specific issue, such as following a course of antibiotics or if diagnosed with a gut issue like IBS. For most people, taking a daily probiotic likely won't do much. Focusing on stress reduction, prebiotics (fibers), and fermented foods is considered much more helpful for daily gut health.
Rationale and Usage: Recommended as a backup when traveling, busy, or struggling to get fresh produce daily. The evidence for promised tangible benefits (immunity, digestion, energy) is weak. Quality is a concern; many lack transparency. A quick smoothie with frozen, nutrient-dense ingredients is often a cheaper and better option, providing fiber.
Rationale and Usage: Recommended to try as a top-up when you cannot get enough protein from whole foods, especially if you are busy, training a lot, or aging. They help build and maintain muscle when combined with strength training. Whole foods are the healthiest main source. Look for third-party testing to avoid contaminants like heavy metals.
These supplements are generally discouraged for routine use because they lack strong human evidence, can be harmful if levels are not deficient, or promote a false sense of security.
Rationale and Usage: Should generally be skipped unless advised by a professional. Major studies have not shown any benefit for living longer or protecting against major diseases. They can provide a false sense of reassurance that allows poor dietary habits to persist. High doses of certain vitamins (like B6) have been linked to a slightly higher risk of cancer in specific groups.
Rationale and Usage: A big skip. Claims are based on theoretical mechanisms or studies performed only in mice. There is no solid evidence behind these supplements in human trials, and their long-term effects are unknown.
Rationale and Usage: Should be skipped unless you have been diagnosed with low iron or anemia following a blood test. If there is no actual deficiency, taking iron has no proven benefit. Too much iron can irritate the gut and potentially increase oxidative stress and inflammation. Increase iron-rich foods (paired with Vitamin C) before supplementation.
Experts express excitement about the potential for whole food supplements (using the "full tool kit" instead of one isolated nutrient). These provide a full spectrum of components, including fiber, healthy fats, proteins, and polyphenols, which work together synergistically.