Your favorite health food store has plenty of supplements. But trying to figure out which nutrient is the best—decoding them—can be tricky. Here is a codebook for three widely used and important supplemental ingredients.
VITAMIN: Vitamin A
What it is: Vitamin A is a description of a variety of nutrients types, including “pro-vitamin A,” more commonly known as beta-carotene.
Where it comes from: Vitamin A is found in a number of carotenoid-rich food sources, including kale, sweet potatoes, carrots, spinach, and mustard greens. Animal sources, like eggs or shrimp, provide vitamin A in the form of retinoids.
Main uses: Vitamin A is essential for proper vitamin D absorption. This is critical since vitamin D affects the heart, brain, and bones. Vitamin A is also required by the immune system for strong macrophage and natural killer cell action. One study found that patients treated with vitamin A following surgery saw an increase in lymphocytes—white blood cells that help prevent infection. However, vitamin A may help modulate the immune system, too. Another clinical study found that it reduced the activity of T lymphocytes that would otherwise attack the myelin sheath of nerve endings in patients with multiple sclerosis.
What to look for: Vitamin A in retinyl forms, like retinyl acetate or retinyl palmitate. This ensures consistent levels of the nutrient. Beta-carotene, a “pro-vitamin A,” needs to be converted by the body before it can provide adequate levels of vitamin A, and some individuals may have a difficult time converting beta-carotene.
Typical dosage level: 2,500 to 5,000 IU of retinyl acetate or palmitate daily.
What it is: Iron is an essential mineral for transporting oxygen throughout the body. It must come from dietary or supplemental sources.
Where it comes from: Iron is found in a number of food sources including beef, broccoli, legumes, liver, quinoa, shellfish, spinach, and tofu.
Main uses: Women who are menstruating, pregnant, or nursing are at an increased need for this nutrient. Children also need adequate iron for proper growth. Along with zinc, iron aids in the production of erythropoietin (EPO), a hormone that helps the body create red blood cells and heal muscle injuries.
What to look for: A preferred form is bisglycinate chelate bound to the amino acid glycine. It is readily absorbed and easy on the stomach. Talk to your healthcare practitioner if you suspect your iron levels are low.
Typical dosage level: Men: 8 mg daily.
Women of childbearing age: up to 18 mg daily.
Children: up to 10 mg daily.
What it is: Comfrey is an herb that has been traditionally recommended to treat pain, burns, bruises, and even broken bones. In fact, one of the plant’s common names was knitbone.
Where it comes from: Comfrey (Symphytum) is found throughout Europe, Asia, and North America.
Main uses: As a topical cream to relieve sore muscles and sprains, heal skin abrasions and burns, and reduce joint swelling. Three compounds in comfrey are associated with its actions: allantoin helps regenerate damaged tissue, choline aids in the recovery of injured blood vessels and nerve endings, and rosmarinic acid inhibits inflammation.
What to look for: A topical cream made from the stems, leaves, and flowers of a special variety of comfrey called Symphytum x uplandicum Nyman, also known as Trauma Comfrey. This plant was developed to be free of compounds called pyrrolizidine alkaloids (PAs). PAs can be toxic to the liver if taken internally. Because Trauma Comfrey is PA-free—and uses only the above-ground parts of the plant—this comfrey cream has been tested in human studies and is safe for adults and children ages 4 years and up.
Typical dosage level: Can be applied as needed.