• Vitamin D (ergocalciferol-D2, cholecalciferol-D3, alfacalcidol) is a fat-soluble vitamin that helps your body absorb calcium and phosphorus. Having the right amount of vitamin D, calcium, and phosphorus is important for building and keeping strong bones.
• Vitamin D is made by the body when skin is exposed to sunlight. Sunscreen, protective clothing, limited exposure to sunlight, dark skin, and age may prevent getting enough vitamin D from the sun. 

• Vitamin D is used to treat and prevent bone disorders (such as rickets, osteomalacia).
• Vitamin D with calcium is used to treat or prevent bone loss (osteoporosis).
• Vitamin D is also used with other medications to treat low levels of calcium or phosphate caused by certain disorders (such as hypoparathyroidism, pseudohypoparathyroidism, familial hypophosphatemia). 
• It may be used in kidney disease to keep calcium levels normal and allow normal bone growth. 
• Vitamin D drops (or other supplements) are given to breast-fed infants because breast milk usually has low levels of vitamin D.

• At normal doses usually has no side effects. 
• Too much vitamin D can cause harmful high calcium levels. Tell your doctor right away if any of these signs of high vitamin D/calcium levels occur: nausea/vomiting, constipation, loss of appetite, increased thirst, increased urination, mental/mood changes, unusual tiredness.

• Before using this medication, tell your doctor or pharmacist your medical history, especially of: high calcium/vitamin D levels (hypercalcemia/hypervitaminosis D), difficulty absorbing nutrition from food (malabsorption syndrome), kidney disease, liver disease.
• Liquid products, chewable tablets, or dissolving tablets may contain sugar and/or aspartame. Liquid products may also contain alcohol. Caution is advised if you have diabetes, liver disease, phenylketonuria (PKU), or any other condition that requires you to limit/avoid these substances in your diet. 

• Selenium is used in the treatment of natural deficiency.
• Selenium is essential for the conversion of thyroxine (T4) to the biologically active thyroid hormone triiodothyronine (T3) thereby it is important in thyroid hormone functioning.
• Selelium is not produced in the body but is needed for the proper immune system and thyroid function.
• It is found in soil, water and some food.

• Selelium is a powerful mineral. It plays a key role in metabolism and the functioning of the Thyroid glands.
• Selenium has antioxidant properties.
• Selenium is used to cure Prostate cancer.
• Some of the diseases due to deficiency of selelium are HIV, Crohn’s disease.
• It is also used to treat diseases like Asthma, Arthritis, Dandruff and Infertility.

• Selenium deficiency produces biochemical changes that might predispose people who experience additional stresses to develop certain illnesses.
• Side effects may include fingernail loss, skin rash, fatigue, irritability and weight loss.

It is observed that overdose of Selelium may increase the chances of non- melanoma (Skin cancer).