Summer sunlight is the most important source of vitamin D, and many people therefore take supplements during the winter months or all year round, as the vitamin plays a role in immune function, blood sugar regulation, mood, cancer prevention, and many other physiological processes. However, there is no guarantee that following official vitamin D guidelines or taking higher doses will optimize blood levels of the nutrient. One reason is that magnesium is required to regulate the metabolism and utilization of vitamin D. Since magnesium deficiency is widespread, this represents a serious and often overlooked public health problem, according to a study from the Vanderbilt-Ingram Cancer Center in the United States.

Side effects such as chronic fatigue syndrome (CFS/ME), brain fog, sleep disturbances, and other neurological issues have been observed both after COVID-19 infections and vaccinations. According to a study published in Nutrition, most of these patients were already deficient in vitamin D, and higher doses of vitamin D that optimize blood levels can help relieve their symptoms. It’s generally advisable to maintain adequate vitamin D levels for the prevention of COVID-19, influenza, and other infections.

Nearsightedness is a vision condition that typically begins in childhood and often worsens during adolescence. However, a diet rich in omega-3 fatty acids from fatty fish appears to reduce the risk of children and adolescents developing nearsightedness, according to a Chinese study published in the British Journal of Ophthalmology. The findings also suggest that the omega-3 fatty acid DHA, found in fatty fish and fish oil supplements, plays a particularly important role in eye health.

Red meat (from four-legged animals) contains complete proteins, vitamin B12, iron, zinc, selenium, choline, and other nutrients that can be difficult to obtain in sufficient amounts from a plant-based diet. According to a population-based study published in Scientific Reports, red meat plays a role in supporting brain health and preventing depression.

Type 2 diabetes is a serious disease that is spreading at epidemic proportions. Many people have prediabetes without knowing it, with signs such as frequent hunger, apple-shaped obesity, insulin resistance, elevated cholesterol, and high blood pressure. Diet and lifestyle play a major role, and according to a study published in Research, fish oil supplementation may reduce the risk that people with prediabetes will go on to develop type 2 diabetes. In their article, the authors take a closer look at how the active omega-3 fatty acids in fish oil - EPA and DHA - help regulate insulin sensitivity, blood glucose, and other metabolic disturbances. In addition, simple dietary changes may further improve blood sugar control and weight management.

Iron deficiency is a global health problem that increases the risk of respiratory infections, anemia, and other serious diseases. Evidence now suggests that iron deficiency in early childhood may prevent immune cells in the lungs from producing key proteins that are essential for fighting viral infections and establishing immune protection. Notably, this effect appears to persist even after the body’s iron stores have been replenished. As a result, children and adolescents who have experienced iron deficiency may remain more vulnerable to viral infections later in life. These findings come from a new US study conducted at Columbia University Irving Medical Center.

Vitamin D deficiency is widespread, and current health authority recommendations are too low for cardiovascular health. A new U.S. study from Intermountain Healthcare in Salt Lake City shows that high-dosed vitamin D supplements, sufficient to optimize blood levels, can halve the risk of a repeat heart attack in patients who have already experienced one. According to the researchers, heart patients should have their vitamin D levels measured and adjusted with appropriate supplementation. However, this remains an underemphasized area, with many lives lost as a result.

Vitamins and minerals are crucial for eye health and vision because they are involved in numerous metabolic processes and act as powerful antioxidants that protect the vulnerable eyes and optic nerve from damage caused by free radicals and oxidative stress. Evidence suggests that deficiencies in vitamins A, B, C, and D, as well as minerals such as magnesium, selenium, zinc, and copper increase the risk of dry eyes, cataracts, AMD, optic nerve damage, and other eye diseases. In addition, being overweight can be an additional risk factor for AMD, diabetic retinopathy, and glaucoma, according to a review published in Nutrients. The authors emphasize that early detection of deficiencies and targeted supplementation can prevent or slow the progression of many eye diseases.

- including serious complications?

Older adults are more easily infected with influenza, COVID-19, and other infections and are also at greater risk that these infections will develop into complications such as pneumonia or acute respiratory distress syndrome (ARDS), which can be potentially life-threatening. One major reason is chronic “inflammaging” caused by widespread deficiencies of vitamin D, vitamin C, selenium, zinc, omega-3 fatty acids, and Q10. This not only increases the risk of infection but also the risk that the immune system will overreact with hyperinflammation, which is the real reason why respiratory infections and sepsis can become life-threatening. Overall, it appears that aging processes increase the need for specific nutrients, and if the immune system is well supplied, it will usually handle most pathogens without causing any symptoms.

PCOS (polycystic ovary syndrome) is the most common cause of involuntary infertility. Women with PCOS often have elevated blood glucose levels due to insulin resistance, which contributes to the development of the condition. However, evidence now suggests that chromium supplementation may have therapeutic effects on insulin sensitivity, blood glucose control, ovulation, and the chance of becoming pregnant. Remarkably, this effect appears to be just as effective as the diabetes drug metformin - yet without side effects. These findings are reported in a meta-analysis published in Endocrinologica, Diabetes and Nutrition. As part of PCOS treatment and blood sugar regulation, it is also recommended to limit carbohydrate intake and place greater emphasis on getting adequate protein and healthy fats with all main meals.

Although health authorities advise against consuming too much salt (sodium), it is still an essential mineral that is crucial for electrolyte and fluid balance. Minor deficiencies can cause symptoms such as fatigue, muscle weakness, dizziness, and headaches. More severe deficiencies can lead to exhaustion, fainting, or other neurological conditions, which in the worst case can be life-threatening. Evidence also suggests that commonly used antidepressant drugs, such as SSRIs and SNRIs, increase the risk of the body lacking this vital mineral. This was shown in a meta-analysis published in BMC Pharmacology and Toxicology. Attention should also be paid to other side effects of antidepressant medication.

When a woman’s ovaries fail to function normally and menopause occurs before the age of 40, the condition is referred to as premature ovarian insufficiency (POI). The accompanying hormonal imbalances cause symptoms such as menstrual irregularities and infertility. Mood swings, fragile mucous membranes, osteoporosis, and other complications may also occur. According to a review article published in Health Science Reports, widespread deficiencies in vitamin D, vitamin E, and selenium appear to increase the risk of premature ovarian insufficiency, whereas supplementation with these nutrients may improve ovarian function and hormonal balance.