In humans, the large intestine is host to more than 1,000 species of microorganisms, mostly bacteria, numbering in the tens of trillions. "Probiotic" in the context of dietary supplements is the theory that by orally consuming specific live bacteria (or yeast) species, it is possible to influence the large intestine microbiota, with consequent health benefits. Although there are numerous claimed benefits of using probiotic supplements, such as maintaining gastrointestinal health, in part by lowering risk of and severity of constipation or diarrhea, and improving immune health, including lower risk of and severity of acute upper respiratory tract infections, i.e., the common cold, such claims are not all supported by sufficient clinical evidence. A review based on interviews with dozens of experts in microbiome research expressed concern about "...how biomedical research is co-opted by commercial entities that place profit over health." The concern is timely, as through 2021, probiotic supplements are expected to be the fastest growing segment of the dietary supplement market worldwide, while at the same time, the global health benefits market for probiotic-containing yogurt (a food, not a dietary supplement) is declining.
When it comes to omega-3 fatty acids (omega = ω) such as EPA and DHA, children may be given cod liver oil and served fish and/or other seafood 2-3 times a week. It is important to check the dose of vitamin A supplied, as it can be toxic in high doses, especially for children. One problem with cod liver oil today is that vitamin D has been removed during processing, thus changing the natural ratio of the two vitamins so that we ingest relatively too much of vitamin A. 
Overall, one should make sure they are eating well and exercising, and then, speak with a nutritionist or physician trained in nutrition to get advice on which supplements you may need. The best resources are physicians trained in nutrition and are board certified physician nutrition specialists (main.uab.edu/Sites/abpns/) and nutritionists with the credential certified nutrition specialist (CNS) as well as Registered Dietitian (RD).
I totally agree about attitude – it can really help you or hurt you and is so valuable to pay attention to. I’ve heard the 90/10 idea also presented as the 80/20 rule where you do your absolute best 80% of the time and don’t kill yourself over the 20%. I think this is a healthy way to approach healthy eating and, as long as you’re making those positive choices 80 or 90 percent of the time, you’re probably going to still see results and feel great. I find each day allowing that to sneak up too much for me so I leave one cheat day to get all that out. It’s still a percentage of my overall eating, just on a day, rather than every day. I hope that makes sense!
As the table above shows, some of the best sources of calcium are dairy products. However, dairy products such as whole milk, cheese, and yogurt also tend to contain high levels of saturated fat. The USDA recommends limiting your saturated fat intake to no more than 10% of your daily calories, meaning you can enjoy whole milk dairy in moderation and opt for no- or low-fat dairy products when possible. Just be aware that reduced fat dairy products often contain lots of added sugar, which can have negative effects on both your health and waistline.
Health care experts haven't reached a consensus on the issue of vitamin and mineral supplements. Many say that if you are healthy and eat a well-balanced diet, you don't need any. But not all of us eat a well-balanced diet. And sometimes, you may follow a nutritious diet and still be deficient. Many women fail to get the adequate amount of vitamins and minerals. Stress increases your need for vitamins and minerals, especially C, B-complex and zinc.
While women tend to need fewer calories than men, our requirements for certain vitamins and minerals are much higher. Hormonal changes associated with menstruation, child-bearing, and menopause mean that women have a higher risk of anemia, weakened bones, and osteoporosis, requiring a higher intake of nutrients such as iron, calcium, magnesium, vitamin D, and vitamin B9 (folate).
Vitamin A can become toxic when taken in large amounts (over 100,000 International Units) on a daily basis over time, as can vitamin D. Substituting beta-carotene for vitamin A can alleviate this risk. Very large doses of minerals taken over long periods may have toxic effects in the body. Dosages far exceeding RDA's of vitamins are not recommended, nor are large doses of other supplements.
Heart-healthy eating is an important way to lower your risk of heart disease and stroke. Heart disease is the number 1 cause of death for American women. Stroke is the number 3 cause of death.1 To get the most benefit for your heart, you should choose more fruits, vegetables, and foods with whole grains and healthy protein. You also should eat less food with added sugar, calories, and unhealthy fats.
The average woman should get 10 to 35 percent of her daily calories from protein. Protein helps prevent muscle tissue from breaking down and repairs body tissues. Sources of animal proteins include meat, fish, poultry, eggs, milk and cheese. Vegetable proteins include dried beans and peas, peanut butter, nuts, bread and cereal. (A three-ounce serving of cooked chicken contains about 21 grams of protein.)
^ Jump up to: a b c Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, Aragon AA, Devries MC, Banfield L, Krieger JW, Phillips SM (2017). "A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults". Br J Sports Med. 52 (6): bjsports–2017–097608. doi:10.1136/bjsports-2017-097608. PMC 5867436. PMID 28698222.
“I brought him two shopping bags filled with a variety of chips to taste. He zeroed right in on the Cheetos. “This,” Witherly said, “is one of the most marvelously constructed foods on the planet, in terms of pure pleasure.” He ticked off a dozen attributes of the Cheetos that make the brain say more. But the one he focused on most was the puff’s uncanny ability to melt in the mouth. “It’s called vanishing caloric density,” Witherly said. “If something melts down quickly, your brain thinks that there’s no calories in it … you can just keep eating it forever.”
Part of the reason why so many women fail to get the amount of iron they need is because one of the best sources of iron is red meat (especially liver) which also contains high levels of saturated fat. While leafy green vegetables and beans are also good sources of iron—and don’t contain high levels saturated fat—the iron from plant foods is different to the iron from animal sources, and not absorbed as well by the body. Other foods rich in iron include poultry, seafood, dried fruit such as raisins and apricots, and iron-fortified cereals, breads, and pastas.