What Is a Riboflavin Deficiency?

Riboflavin (vitamin B2), whether as a flavin single nucleotide or a flavin adenine dinucleotide, plays an essential coenzyme role in many oxidation-reduction reactions related to carbohydrate metabolism. Riboflavin deficiency can cause Oral, eye, skin, and reproductive damage

Riboflavin deficiency

Primary riboflavin deficiency is related to insufficient consumption of milk and other animal products. Secondary deficiency is more common in chronic diarrhea, liver disease, chronic alcoholism, and postoperative nutritional infusion.

Riboflavin deficiency symptoms check

The most common signs are pale and macerated mucosa (angular inflammation), and the surface of the lips is cinnabar (lip cracks), followed by superficial linear cracks, which can leave scars when healed. These lesions are affected by Candida albicans When infected, it produces off-white highly proliferative damage (candidal stomatitis). The tongue surface can be magenta. Skin damage is common in nasolabial folds, wings of the nose, ears, eyelids, scrotum, and labia majora. These areas become It becomes red, scaly, and has too much fat. In addition, sebum accumulates in the hair follicles, causing sebum disorders or shark skin.

Rare corneal neovascularization and epithelial keratitis cause tearing and photophobia. Riboflavin for nutritional amblyopia is effective.

Urinary excretion of riboflavin per gram of creatinine <30g can be accompanied by the production of clinical signs of riboflavin deficiency. Increased erythrocyte glutathione reductase activity caused by riboflavin is an early sign of riboflavin deficiency.

Causes of riboflavin deficiency

Riboflavin is an important component of the flavin coenzyme required for normal intracellular oxidation and reduction, and is closely related to the metabolism of fat, sugar and protein. Riboflavin has limited reserves in tissues and is quickly consumed. It is estimated that the daily human nutritional requirement is 0.6mg / 4186.8J (1000 kcal). In the absence of it, it can cause a series of damage in experimental animals, but in humans it has a slight effect, mainly causing skin and mucosal damage. ^[1]

The causes of riboflavin deficiency may be:

insufficient supply in the diet;

Sudden changes in eating habits or improper cooking and eating methods;

Consumption increases during pregnancy and heavy physical labor, but the amount of riboflavin does not increase accordingly;

Gastrointestinal diseases, hyperthyroidism, advanced cancer, chronic alcoholism, fever, and chronic wasting diseases affect the absorption or increase of riboflavin;

Oral contraceptives and other drugs, especially phenazines, tricyclic antidepressants, boric acid, etc. can affect riboflavin metabolism or interact with riboflavin to cause riboflavin deficiency.

Clinical manifestations of riboflavin deficiency

The individual symptoms of riboflavin deficiency are not specific, but a comprehensive observation can prompt a diagnosis of the disease. These symptoms mainly include scrotal inflammation, glossitis, cheilitis, and cheilitis.

(1) Scrotal inflammation is the earliest and most common manifestation, and can be divided into erythema type, papular type and eczema type.

The erythema type is the most common type. It is pale red in the early stage, symmetrically distributed on both sides of the scrotum, and the edges are bright red. Later, the surface is covered with shiny, adhesive, off-white or brown scales. Soft and non-wetting.

The pimple papular type is a large group of scattered round needles with large needles and large soybeans, which are covered with tan thin pimples. They can also be fused into a single piece, and may be distributed on one side of the scrotum in the early stage.

Eczema-type scrotum limited local or diffuse infiltration hypertrophy, lichenification, the same as chronic eczema. May have exudate, scab, occasionally cleft palate, chronic passage. Elderly skin lesions can extend to the penis trunk or the inner thigh.

In addition to scrotal skin lesions, greasy scaly skin lesions similar to seborrheic dermatitis can also occur in the center of the face, nasolabial folds, nasal wing, inner and outer ridges of the eyelids, and earlobe.

(2) In the early stage of glossitis, the mushroom-shaped nipples are the size of a needle tip, and the contour nipples are a hypertrophic papule the size of a soybean. The middle part of the tongue is a bright red spot with a wide front end and a narrow gourd-shaped rear end. In severe cases, the whole tongue is bruising, and the swelling is obvious. Later, the nipples became smaller or disappeared, and the tongue surface atrophied smoothly, with fissures of different sizes and depths, and consciously felt pain.

(3) Cheilitis is mainly found in the lower lip. Lips are dry, desquamated, and pigmented, and occasionally flushed, eroded, and cracked.

(4) Keratitis: The maceration of the mouth, whitiness, erosion, cleft palate, and dementia, tends to be infected, and can scar after healing.

Other mucosal symptoms include photophobia, tearing, conjunctivitis, superficial keratitis, corneal opacities and even ulcers, nasal vestibular crusts, and cleft palate. ^[2]

Diagnosis and treatment of riboflavin deficiency

The above damage is not unique to riboflavin deficiency. Lip cleft lip can also be caused by vitamin B6 deficiency, missing teeth or inadequate installation of the teeth. Seborrheic dermatitis and eye lesions can occur in many cases. Therefore, the diagnosis of riboflavin deficiency It is not possible to rely solely on medical history and only suggestive lesions; laboratory tests to rule out other causes and therapeutic trials may be necessary.

Oral administration of riboflavin 10 to 30 mg daily until significant effect appears; thereafter, 2 to 4 mg daily until healing, riboflavin can also be administered intramuscularly, 2 to 20 mg daily, 1 Multiple or divided injections.

Riboflavin deficiency test items

A) Pathological examination showed that the epidermis of the scrotal skin lesion was significantly keratinized, and the granular layer was reduced or disappeared. In severe cases, except for excessive keratinization of the epidermis, the pigmentation of the underlying cells was reduced or disappeared. Capillaries in the dermis are dilated to varying degrees. Keratinization of the epithelium such as the lips and tongue is also seen, and the tissues of the atrophy of the tongue and nipples also significantly shrink.

(B) Riboflavin is measured in grams of creatinine per gram. For diagnostic reliability, a 24-hour urine test is best collected. The result was <27 g / gram of creatinine, suggesting that the vitamin B2 deficiency in adults was higher than that in adults.

(3) Urinary excretion load test: An oral load dose of riboflavin 5 mg was collected for 4 hours to determine the excretion amount. Adult excretion <1000g is riboflavin deficiency.

(IV) Erythrocyte glutathione reductase (EGR) functional test. This test was clinically selected as the latest simple and convenient method to evaluate the nutritional status of vitamin B2. The test uses the "FAD effect" as a measure. After adding FAD, the enzyme activity increased by more than 20%, suggesting insufficient riboflavin storage in the tissue. ^[3]