in discoloration of the nails. omega-3 fatty acids can help lubricate and moisturize nails, giving them a shiny appearance. these fatty acids may also reduce inflammation in the nail bed, which nourishes and promotes the health of cells that give rise to the nail plate. a lack of omega-3 fatty acids could contribute to dry and brittle nails. protein is a building material for new nails; therefore, low dietary protein intake may cause anemia and the resultant reduced hemoglobin in the blood filling the capillaries of the nail bed reflects varying amounts of light incident on the nail matrix resulting in lighter shades of pink ultimately resulting in white nail beds when the hemoglobin is very low. when hemoglobin is close to 15 or 16 grams, most of the spectrum of light is absorbed and only the pink color is reflected back and the nails look pink. essential fatty acids play a large role in healthy skin as well as nails. splitting and flaking of nails may be due to a lack of linoleic acid. iron-deficiency anemia can lead to a pale color along with a thin, brittle, ridged texture. iron deficiency in general may cause the nails to become flat or concave, rather than convex. as oxygen is needed for healthy nails, an iron deficiency or anemia can lead to vertical ridges or concavity in the nails. rdas for iron vary considerably depending on age and gender. the recommendation for men is 8 mg per day, while that of women aged 19–50 is 18 mg per day. after women hit age 50 or go through menopause, their iron needs drop to 8 mg daily. society and culture fashion toenails painted magenta manicures (for the hands) and pedicures (for the feet) are health and cosmetic procedures to groom, trim, and paint the nails and manage calluses. they require various tools such as cuticle scissors, nail scissors, nail clippers, and nail files. artificial nails can also be fixed onto real nails for cosmetic purposes. a person whose occupation is to cut, shape and care for nails as well as to apply overlays such as acrylic and uv gel is sometimes called a nail stylist. the place where a nail stylist works may be a nail salon or nail shop or nail bar.nail art acrylic nails are made out of acrylic glass (pmma). when it is mixed with a liquid monomer (usually ethyl methacrylate mixed with some inhibitor) it forms a malleable bead. this mixture begins to cure immediately, continuing until completely solid in minutes. acrylic nails can last up to 21 days but can last longer with touch-ups. to give acrylic nails color, gel polish, nail polish, and dip powders can be applied. painting the nails with colored nail polish (also called nail lacquer and nail varnish) to improve the appearance is a common practice dating back to at least 3000 b.c. with the rise of smartphones, some analysts have noted a trend of the nelfie (nail selfie), wherein people share their nail art online. gel nails can be utilized in order to create artificial nail extensions, but can also be used like nail polish. they are hardened using ultraviolet light. they last longer than regular nail polish and do not chip. they have a high-gloss finish and last for two to three weeks. nail wraps are formed by cutting pieces of fiberglass, linen, silk fabric, or another material to fit on the surface of the nail (or a tip attached prior), to be sealed onto the nail plate with a layer of resin or glue. they do not damage the nail and also provide strength to the nail but are not used to lengthen it. it can also be used to fix broken nails. the treatment is however more expensive. with the dip powder method, a clear liquid is brushed onto a nail and the nail is then placed into pigmented powder. dip nails tend to last about a month, 2-3 weeks longer than gel and acrylic nails. it can be worn on natural nails, or with tips to create an artificial nail. dip powder nails do not require any uv/led light to be cured, instead they are sealed using an activator. the quickest way to remove dip powder is to drill, clip off, or buff out layers of the powder so, when they are soaking in acetone, they slide right off. length records guinness world records began tracking record fingernail lengths in 1955, when a chinese priest was listed as having fingernails 1 foot 10.75 inches (57.79 cm) long. the current record-holder for men, according to guinness, is shridhar chillal from india who set the record in 1998 with a total of 20 feet 2.25 inches (615.32 cm) of nails on his left hand. his longest nail, on his thumb, was 4 feet 9.6 inches (146.3 cm) long. the record-holder for women is lee redmond of the u.s., who set the record in 2001 and as of 2008 had nails with a total length on both hands of 28 feet (850 cm), with the longest nail on her right thumb at 2 feet 11 inches (89 cm). evolution in primates nails are a distinguishing feature of the primate order. the nail is an unguis, meaning a keratin structure at the end of a digit. other examples of ungues include the claw, hoof, and talon. the nails of primates and the hooves of running mammals evolved from the claws of earlier animals. in contrast to nails, claws are typically curved ventrally (downwards in animals) and compressed sideways. they serve a multitude of functions—including climbing, digging, and fighting—and have undergone numerous adaptive changes in different animal taxa. claws are pointed at their ends and are composed of two layers: a thick, deep layer and a superficial, hardened layer which serves a protective function. the underlying bone is a virtual mold of the overlying horny structure and therefore has the same shape as the claw or nail. compared to claws, nails are flat, less curved, and do not extend far beyond the tip of the digits. the ends of the nails usually consist only of the "superficial", hardened layer and are not pointed like claws. with only a few exceptions, primates retain plesiomorphic (original, "primitive") hands with five digits, each equipped with either a nail or a claw. for example, nearly all living strepsirrhine primates have nails on all digits except the second toe which is equipped with a grooming claw. tarsiers have a grooming claw on second and third toes. less commonly known, a grooming claw is also found on the second pedal digit of owl monkeys (aotus), titis (callicebus), and possibly other new world monkeys. the needle-clawed bushbaby (euoticus) has keeled nails (the thumb and the first and the second toes have claws) featuring a central ridge that ends in a needle-like tip. a study of the fingertip morphology of four small-bodied new world monkey species indicated a correlation between increasing small-branch foraging and: expanded apical pads (fingertips), developed epidermal ridges (fingerprints), broadened distal parts of distal phalanges (fingertip bones), and reduced flexor and extensor tubercles (attachment areas for finger muscles on bones). this suggests that whereas claws are useful on large-diameter branches, wide fingertips with nails and epidermal ridges were required for habitual locomotion on small-diameter branches. it also indicates keel-shaped nails of callitrichines (a family of new world monkeys) is a derived postural adaptation rather than retained ancestral condition.