Zinc is an essential mineral and has a multitude of biological roles because it is a functional component of over 300 enzymes that rely on zinc to be able to catalyze chemical reactions. Zinc also participates in the structure of important proteins and is involved in the regulation of gene expression.
Zinc is obtained from the diet. Oysters contain substantially more zinc than any other food, although red meat (e.g., beef, pork) and poultry provide the majority of zinc in the American diet. Other good sources of zinc are legumes, nuts, and dairy products. In some countries, the flour used in cereals are fortified with zinc.
The potential benefits derived from supplementation with zinc seem to be at least partly attributable to zinc’s anti-inflammatory and antioxidant properties. Zinc supplementation has been shown to reduce the duration of respiratory tract infections and the common cold.
Adequate dietary intake of zinc is essential for proper growth and development during pregnancy and throughout infancy, childhood, and adulthood. Additionally, zinc is required for normal development, activity, and function of both innate and adaptive immune cells; proper function of pancreatic beta-cells and glucose uptake; and spermatogenesis and normal sperm physiology (e.g., sperm motility).
In the brain, zinc ions inhibit N-methyl-D-aspartate (NMDA) receptors, which is relevant to depression because this condition is characterized by elevated glutamatergic neurotransmission (to which NMDA receptors contribute). Zinc may also benefit depression by increasing brain-derived neurotrophic factor levels.
Day: June 26, 2025
VITAMIN D AND MEN’S HEALTH
Vitamin D is a fat-soluble nutrient and one of the 24 micronutrients vital for human survival. The sun is the primary natural source, stimulating vitamin D production in the skin, but it can also be found naturally in oily fish and eggs, and is often added to milk and milk alternatives. Vitamin D supplementation is linked to a range of benefits, including enhanced immune health, stronger bones, and overall well-being. It may also lower the risk of cancer mortality, diabetes, and multiple sclerosis.
The effects of vitamin D likely depend on a person’s circulating levels of 25-hydroxyvitamin D (25(OH)D; a form of vitamin D that is measured in blood samples to determine vitamin D status), and many of the benefits of supplementation will only be seen once a deficiency is reversed. Vitamin D exists in two forms: D2 (found in mushrooms) and D3 (found in animal foods), with D3 being more bioavailable. D3 supplements are typically derived from lanolin, which some vegetarians may accept, whereas vegans should seek D3 sourced from lichen extracts.
Dietary sources of vitamin D3 include fatty fish, fish liver oil, beef liver, egg yolks, and UV-exposed mushrooms. Many foods in the U.S. are fortified with vitamin D, such as dairy products, plant-based milks, orange juice, and breakfast cereals. Vitamin D exerts its effects by binding to and activating the vitamin D receptor (VDR). Upon binding vitamin D, the VDR functions as a transcription factor, regulating the activity of over 1,000 different genes. Vitamin D also works through “non-genomic” mechanisms, causing rapid activation of various signaling pathways within the cell.