Most of us believe we eat relatively healthy, well-balanced diets, filled with vital nutrients, vitamins and minerals. It may come as a shock, but many of our diets lack vital vitamins, nutrients and minerals needed for growth, development, immunity and overall health. Vitamin A (from winter greens), vitamin E (from sunflower seeds), omega-3 (from wild salmon), calcium (from milk and dairy products), magnesium (from raw pumpkin seeds) and zinc (from red meat, fish and poultry) are the nutrients most often consumed below the recommended levels. In addition, females continue to consume low levels of phosphorous (from meat, fish and diary products) and iron (from lean meat, dried fruit, cereals, green vegetables, when accompanied by vitamin C). Our diets are, however, high in total fat and saturated fats, and sodium intakes continue to be much higher than recommended values.

Vitamins, nutrients and minerals are crucial for health. For example, calcium’s function is to form bone and teeth, but you may not know that it is also vital for blood clotting and nerve transmission. Magnesium helps decrease blood pressure, and phosphorous aids metabolic energy control. Sodium helps with proper nerve function and muscle contraction, but too much can lead to vomiting and hypertension.

More recently, phytonutrients, a new group of nutritional compounds, have been discovered. These compounds are derived from fruits and vegetables and other plant foods, such as carotenoids, flavonoids and limonoids, and play a very important role in determining our disease risk. They are highly cardio-protective, chemo-protective, neuro-protective, but unfortunately, our diets no longer contain adequate amounts for optimum health.

Plausible explanations put forward in the scientific literature to explain these deficits include our fad diets and bad eating habits. Low-carbohydrate, high-protein diets, meal replacements, detox diets and the many more diets on the market all promise to make you thinner, healthier and happier, but tend to lead to yo-yo dieting and, in many cases, a deficiency in vital nutrients. In addition, we consume vast amounts of processed and fast foods. Not only has this led to nutritional deficiencies — for example, consuming sodas impedes the uptake of calcium, thereby increasing the risk of osteoporosis — but fast and processed foods have also contributed to our current and ever-increasing obesity epidemic, which, tragically, our pediatric population has not eluded.

Of course, we would not have deficits in our diets if we just took a good vitamin supplement, right? Unfortunately, many of the vitamins currently on the market are very poorly designed by companies that don’t know what they are producing, and are consumed by people who don’t know what they are eating. In general, people eating a healthy balanced diet do not need to take any supplements. In some cases, however, supplements from reputable companies may be necessary, such as during pregnancy and lactation, for people who are sick and also for athletes.

The simplest way to a happier, healthier you for 2011 maybe to banish the fad diets and go back to basics, cooking your own fresh foods and eating five portions of fruit and vegetables a day.   

Louise Kelly, Ph.D. is an assistant professor of exercise science at California Lutheran University in Thousand Oaks.